# Aquarium Science > Based on Science and Logic > Generated by All in One SEO v5.0.3, this is an llms.txt file, used by LLMs to index the site. ## Sitemaps - [XML Sitemap](https://aquariumscience.org/sitemap.xml): Contains all public & indexable URLs for this website. ## Posts - [Something Smells Fishy](https://aquariumscience.org/something-smells-fishy/) - [Website Updates](https://aquariumscience.org/website-updates/): This website has been updated to use the Genesis WordPress Platform, the Monochrome Studiopress Chile Theme. Modifications done by the author's son. ## Pages - [Homepage](https://aquariumscience.org/): Aquarium Science This is a website dedicated to freshwater aquariums. It is based on SCIENCE AND LOGIC, not on parroted internet “advice”, anecdotal “It worked great for me“, or the marketing hype of some profit-driven marketer. Introduction What needs to be emphasized is that this research has pointed out that there are a huge number - [7.2.11. Ceramics](https://aquariumscience.org/7-2-11-ceramics/): There is a huge amount of misinformation out there about the efficacy of ceramic media. Ceramics are NOT good media for aquarium filters. They have the following shortcomings: Low effective surface area which gives poor biofiltration Shed small abrasive particles which take out pumps Do not do any denitrification Very high cost Throw out the - [2.12. Beneficial Bacteria](https://aquariumscience.org/2-12-beneficial-bacteria/): There are several general types of "beneficial bacteria" involved in oxidizing ammonia to relatively safe nitrate in the freshwater aquarium. Scientists call these organisms “nitrifying” bacteria (AOBs) and archaea (AOAs). Rather than getting into a long winded discussion of bacteria versus archaea we will use the term “beneficial bacteria” for both the nitrifying bacteria and - [7.4.6. Purigen](https://aquariumscience.org/7-4-6-purigen/): Seachem Purigen is an interesting well hyped extremely expensive ($45-$60 for one liter) product that is supposedly unlike any other filtration product. It is supposedly “not a mixture of ion exchangers or adsorbents, but rather a unique macro-porous synthetic polymer”. Purigen is repackaged industrial bulk non-ionic polymeric adsorbent resin: specifically AmberLite XAD7HP (now DuPont). The - [7.2.9. Lava Rock](https://aquariumscience.org/7-2-9-lava-rock/): Lava rock has a very convoluted surface which we initially thought would mean it must be doubled in surface area calculations. This turned out not to be true. Lava rock is best used in aquariums in the range of ¼ to ½ inch diameter. You can get small lava rock from the internet. Joey (the - [7. Filter Media](https://aquariumscience.org/7-filter-media/): A Confession The author would like to be able to say he knew what this testing revealed all along and has been using 100% foam, pot scrubbers or K1 in all his many canisters over the 56 years he has been keeping aquariums. That would be a lie. For some 45 years the author had - [17.7. Aquarium Bettas](https://aquariumscience.org/17-7-aquarium-bettas/): Bettas are a very misunderstood fish. Like goldfish, they have been the object of a very concerted campaign by PETA (People for the Ethical Treatment of Animals) to stop the keeping of bettas in small containers. “A single betta requires five gallons of water minimum” has become the mantra (some say ten gallons!). That mantra - [5. Ammonia, Nitrite, Nitrate and Chlorine](https://aquariumscience.org/5-ammonia-nitrite-nitrate-and-chlorine/): Ammonia, Nitrite, Nitrate, and Chlorine are the four water parameters of interest here. Many people consider them all to be potent poisons of fish. In truth, only chlorine is a potent poison for fish. Ammonia and nitrite are only toxic at some surprisingly high levels of the toxin, dependent on pH. And nitrate is relatively - [14.11. Fish Electrocution](https://aquariumscience.org/14-11-fish-electrocution/): All experienced fish keepers have screwed up and shorted out a heater in the aquarium. The typical scenario is that a hobbyist drops the water level in their tank by 50% to do a water change and forgets to turn off the heater. When the hobbyist then adds a bucket of water back into the - [11.12. Neon Disease](https://aquariumscience.org/11-12-neon-disease/): Neons get a lot of diseases. . Neons are not a Beginner Fish. . Neons need very clean, bacteria free water to do well. . A Predicate Note that neons are just like any other fish in that they can die very rapidly under certain common conditions. Let us say you have a tank of - [14.12. Silicone](https://aquariumscience.org/14-12-silicone/): When a glass aquarium springs a leak at the silicone seals, the hobbyist will need to either reseal or rebuild the aquarium. To do that one needs at least one tube of silicone rubber. People on social media are always asking “what is the best silicone for resealing my aquarium?”. We will attempt to answer - [Get Started](https://aquariumscience.org/aquarium-science/): Aquarium Science Author: David Bogert Index: 1 Basics, 2 Cycling, 3 Food, 4 Water, 5 Toxins, 6 Filtration, 7 Media, 8 Filters, 9 Aeration, 10 Diseases, 11 Symptoms, 12 Treatment, 13 Stocking, 14 Equipment, 15 Plants, 16 Algae, 17 Fish, 18 Maintenance This is a website dedicated to freshwater aquariums. It is based on SCIENCE AND LOGIC, not on parroted internet "advice", anecdotal "It worked great for - [1.1.10. Plants and the New Hobbyist](https://aquariumscience.org/1-1-10-plants-and-the-new-hobbyist/): The author does not want to discourage newcomers to the hobby. But when it comes to plants there simply is a problem. Plants are not as easy as everyone says they are. Newcomers to the hobby should skip the plants and start with a lightly stocked “fish only” aquarium with several small fish and plastic - [15.17. Father Fish Aquariums](https://aquariumscience.org/15-17-father-fish-aquariums/): Another system that uses a filtered "natural" planted system with some air stone aeration can be perused in the popular YouTube channel "Father Fish", Lou Foxwell (great YouTube channel, even if, like all of us "older" folks, he tends to ramble on a bit). The Father Fish system he uses is somewhat different than most - [7.2.14. BioHome Filter Media](https://aquariumscience.org/7-2-14-biohome-filter-media/): Biohome is a VERY expensive type of ceramic aquarium filter media. It is NOT a good media. This ceramic media is heavily marketed by a YouTube guru called the "Pondguru" from the United Kingdom. If I want a laugh, I watch this snake oil salesman's videos. The videos are all about how there is a - [10.13.5. Bryozoans and Stentors](https://aquariumscience.org/10-13-5-bryozoans-and-stentors/): Bryozoans One interesting little critter that looks much like a hydra but is a different type of animal is something called a "bryozoan". It acts and looks much like hydra but tends to occur in clusters and colonies, often quite large. It is very rarely seen in the aquarium. The little bodies have many more - [4.6.1. Trace Additives](https://aquariumscience.org/4-6-1-trace-additives/): Now be forewarned, I’m not a big fan of Seachem. The amount of pseudoscientific bedazzlement and marketing hype they put in with all their products is just nauseating. And they have threatened me with a libel suit. I don’t like being threatened. So I am a "biased" observer. That being said, Seachem sells four “trace” - [4.11. Tank Syndromes](https://aquariumscience.org/4-11-tank-syndromes/): When anyone on social media says they have a sick fish the first question will always be “What are your water parameters?”. Now normally the physical symptoms on the fish itself are much more useful for diagnosing a fish disease than the “water parameters”. But there are exceptions. There are three specific “tank syndromes” where - [18.7. Sick Tank Syndrome](https://aquariumscience.org/18-7-sick-tank-syndrome/): A very common question on the aquarium forums is along the lines of: “My water parameters are perfect (0 ammonia, 0 nitrites and only 5 nitrates) yet my fish keep dying. Why are my fish dying?” This person probably has some version of the “sick tank syndrome”. A more descriptive term would be "perfect but - [5.5.4. Stress Coat Products](https://aquariumscience.org/5-5-4-stress-coat-products/): There are a whole series of “Stress Coat” products that are supposed to help fish during transport and during introduction to new aquariums. They are ALL pure marketing hype and worthless. Most of them also remove chlorine and chloramine but a few of them claim this and do not do this. This ambiguity makes these - [8.5.2. DIY Undergravel Filter](https://aquariumscience.org/8-5-2-diy-undergravel-filter/): Below we go into two designs of DIY undergravel filters. The first is a somewhat expensive but robust PVC pipe design. The second design is a cheaper but less robust design which uses a plastic grid from the needlepoint hobby. DIY PVC Pipe Undergravel Filter A few commentators have now ask about do-it-yourself undergravel filters - [11.19. Gas Bubble Disease](https://aquariumscience.org/11-19-gas-bubble-disease/): “Gas Bubble Disease” is where many gas bubbles form in a fish and literally cause the fish to get the “bends”. Water that is very cold can absorb much more air in solution than warm water. Say warm water (25 degrees C.) can have 20 ppm air dissolved in it while cold water (10 degrees - [15.16. Natural Aquarium](https://aquariumscience.org/15-16-natural-aquarium/): A Caveat ALL "natural" approaches I've seen have one problem. They all have a yellow tint to the water. And neither Purigen or activated carbon remove this slight yellow tinge. Most people don't seem to even notice it. But I do and it bothers me. And those approaches to a "natural" all tend to give - [15.15. Sterilizing Plants](https://aquariumscience.org/15-15-sterilizing-plants/): There are a whole host of "dips" and "soaks" for plants which supposedly "sterilize" the plants or kills all pathogens, algae, snails and worms on the plants. The YouTube channel "Girl Talks Fish" (superb channel, I highly recommend it!) tested a whole bunch of dips and soaks on snails (and ONLY snails). To make a - [1.1.14. Aquarium Maintenance](https://aquariumscience.org/1-1-14-aquarium-maintenance/): If one listened to all the well-meaning but ill-informed commentators on social media about aquarium maintenance one would be doing the following: Do 50% water changes every week Thorough gravel vacuuming every week Mechanical media cleaning once weekly Bleach brown algae off the ornaments every two weeks Filter media cleaning and/or replacement once a month - [17.11.4. Food for Discus](https://aquariumscience.org/17-11-4-food-for-discus/): University research has shown discus are somewhat less forgiving than most fish when it comes to fish food. Commercial dry foods generally are not "optimum" for discus, even if they have a label that says "For Discus". But note the word "optimum". Perfectly satisfactory results can be had with most pelleted commercial fish food as - [17.11.6. Breeding Discus](https://aquariumscience.org/17-11-6-breeding-discus/): Breeding discus is a very misunderstood topic. It all has to do with what black water is. The native waters of discus are typically "black water" biotopes. Black water is water which is so low in dissolved solids that bacteria cannot grow. Bacteria need some sodium chloride and other salts in order to metabolize well - [17.11.5. Discus Pheromones](https://aquariumscience.org/17-11-5-discus-pheromones/): A pheromone is a chemical that an animal produces which changes the behavior of another animal of the same species. Think of a pheromone as a "smell". These "smells" can be very complex and have a lot of components. There is one large supplier of discus which started out their huge discus breeding faculty with - [17.11.3. Water for Discus](https://aquariumscience.org/17-11-3-water-for-discus/): Many think that discus MUST be kept at a high temperature (840 F. to 900 F.) in water which has a low TDS and a pH between 6.0 and 7.0. This is ONLY true if one is trying to raise competitive discus which are as large as possible. Adult discus in a decorative aquarium will - [17.11.2. Filtration for Discus](https://aquariumscience.org/17-11-2-filtration-for-discus/): I found the key to decorative discus is ultra-crystal-clear water with NO bacteria counts and a HUGE amount of biofiltration. And I mean HUGE! For decorative discus one should ideally have a sump of at least 40% of the aquarium size (a 50 gallon aquarium needs at least a 20 gallon sump). This sump should - [17.11.1. Discus Husbandry](https://aquariumscience.org/17-11-1-discus-husbandry/): A Predicate Example On October 1, 2023 Dan Hiteshew (Everyday Fishkeeping) posted a YouTube video entitled "Suck This, Discus Keepers". Dan had two discus breeding in a community tank which was not treated in any special way. It had nitrates over 80 ppm. It was fed flake food. The filtration wasn't the greatest in the - [17.11.7. Discus Photos](https://aquariumscience.org/17-11-7-discus-photos/): 17.11.7. Discus Photos Here is a page of photos of discus tank which will give one an idea of how varied the selection of discus breeds can be: . Information on - [17.12. Axolotl](https://aquariumscience.org/17-12-axolotl/): Axolotls are a lot like a cold-water discus in what their "optimum" conditions are. As with discus, there are two opposed methods of keeping axolotl. If one tries to do anything other than these two methods, there CAN be problems. The two methods are: 1, The “ultra-clean way”. This is where everything is frequently changed - [15.6.6. Measuring CO2](https://aquariumscience.org/15-6-6-measuring-co2/): There are two ways to measure CO2 levels in the aquarium: Glass reactors ("drop checkers") are slow, they give you what is in essence an average over three hours or so. And they are difficult to read. But they are dependable under many sets of conditions for those aquarists wanting to hold 30 ppm CO2 - [15.5.7. DIY Fertilizers](https://aquariumscience.org/15-5-7-diy-fertilizers/): Do it Yourself Fertilizers Some hobbyists with planted aquariums want to use the same type of fertilization program an expensive commercial aquarium fertilizer will provide, but at a much lower cost. This article tells on how to make a do-it-yourself fertilizer which is MUCH cheaper. Optimum NPK Ratio The "NPK" ratio is a series of - [15.5.5. DIY Epiphytic Fertilizer](https://aquariumscience.org/15-5-5-diy-epiphytic-fertilizer/): Rooted Plants versus Epiphytes and Floating Plants Some planted aquariums have epiphytes (plants that grow on wood or rock) and floating plants. Tabs put into the substrate obviously won't work too well for these epiphytes as they do not have roots into the substrate. So they have to be supplied phosphate and iron through the - [15.5.6. Fish Food Fertilizer](https://aquariumscience.org/15-5-6-fish-food-fertilizer/): Adding a "natural" fertilizer like extra fish food is not a good idea if there is little biofiltration together with fish in the aquarium. The "natural" fertilizer produces dissolved organic compounds which feed heterotrophic bacteria. These bacteria cloud the water and compromise the fish’s immune system in the aquarium. But this type of fertilization can - [15.5.2. Fertilizer Programs](https://aquariumscience.org/15-5-2-fertilizer-programs/): There are several planted aquarium commercial fertilizer “lines” of several products, all designed to be used together in a "program". Easily 80% of the "fertilizers" in "programs" are pure unadulterated snake oil designed solely to get you to part with sizable chunks of money. The remaining 20% can be made DIY for about 10% of - [18.1.4. Softened, RO, DI, TDS](https://aquariumscience.org/18-1-4-softened-ro-di-tds/): Any water you can drink is fine for almost any fish. Plants are a little more touchy. The only time one can have problems is: If TDS or total dissolved solids are less than 60 ppm (rare!), fish can have problems If GH (general hardness) is less than 3, plants, snails and shrimp can have - [2.5.2. Rapid Fish-in Cycling](https://aquariumscience.org/2-5-2-rapid-fish-in-cycling/): One problem many get into is how to reasonably make a fish-in cycle work to add a decent number of fish in three to six weeks. If one does fish-in cycling properly, you only lightly feed a small number of fish. So how does one get up to a decent number of fish in less - [8.7.8. Small DIY Filters](https://aquariumscience.org/8-7-8-small-diy-filters/): People with small tanks need inexpensive ways to filter these aquariums. While I heartily recommend under-gravel filters for these small aquariums, many hobbyists do not want to go that way. They want a planted aquarium, soiled aquarium, or they want a sand substrate. Sponge filters are not liked by many because they are ugly. So - [8.6.7. Foam Sump](https://aquariumscience.org/8-6-7-foam-sump/): 8.6.7. Foam Sump There is one type of foam sump that is VERY attractive to those who are cowed by the complexity or the noise of a fluidized bed sump. It is a foam/ 2 wavemaker sump. This is what it looks like: This will have about 60% of the biofiltration capacity of the same - [14.15. Aquarium Aesthetics](https://aquariumscience.org/14-15-aquarium-aesthetics/): In the photo above, note the black hole in under the wood one third of the way in from the left and one third up from the bottom. We discuss this below under "Rule of Thirds". Aquarium Aesthetics This is another one of those subjects which are just opinions. What I going to tell you - [15.14. Low Tech Planted Aquariums](https://aquariumscience.org/15-14-low-tech-planted-aquariums/): Probably three-fourths of the planted aquariums are low-tech planted tanks. The genesis of most low-tech planted aquariums is simple. It is a beginner tank that got some beginner plants put into it and the whole thing worked, more by accident than by design. A beginner sets up their first aquarium. They put down some aquarium - [16.2.7. Chihiros Doctor](https://aquariumscience.org/16-2-7-chihiros-doctor/): Many planted aquarium photos from Europe show a little fan-like device in one corner. These are the "Chihiros Doctor" (the Twinstar Unit is very similar and does the same thing). The units are somewhat expensive ($73 to $110). This device supposedly controls algae. This device is nothing more than a “sneaky” way to use chemicals - [7.1.1. Cost of Filter Media](https://aquariumscience.org/7-1-1-cost-of-filter-media/): This article has been rewritten about a dozen times. The availability and price of all the aquarium media have been on a rollercoaster. Up-down, up-down. Trying to pin the numbers down has been difficult. And there is a big problem with something called “buying in bulk”. If one has a large aquarium with a large - [13.1. Stocking Opinions](https://aquariumscience.org/13-1-stocking-opinions/): 13.1.Stocking Opinion in Depth Stocking is a very controversial topic. People on social media will adamantly argue that keeping a single betta in anything less than a 5 gallon is incredibly cruel. Many say Lake Malawi Cichlids can’t be kept in anything less than a 50-gallon tank and even that should only have a maximum - [17.2.1. Blackwater Biotope](https://aquariumscience.org/17-2-1-blackwater-biotope/): Summary of Blackwater The term "blackwater" refers to soft, acidic water which is deep brown in color, like clear tea. The dark brown color is due to humic organic acids in the water. Many river systems of northern South America including the Rio Negro and the Orinoco have blackwater. Some streams and swamps in Southeast - [14.14. Cleaning Old Aquariums](https://aquariumscience.org/14-14-cleaning-old-aquariums/): Many, including myself, keep a close eye on Craig’s list for any cheap glass aquariums which come up for sale. These tanks often have a hard white deposit on the waterline. This white deposit is best removed with a pumice stone, stainless-steel pocketknife or steel wool. Read on if you want to become bored. What - [1.1.12.2. Unimportant Aquarium Parameters](https://aquariumscience.org/1-1-12-2-unimportant-aquarium-parameters/): This website uses a multi-level approach to any subject. The easiest explanation is first and then there are typically a series of more and more complex explanations. In the last article we looked at the five things that allow fish to thrive. This is a link to that article: 1.1.12. How to Make Fish Thrive - [2.15. Cycling a Planted Aquarium](https://aquariumscience.org/2-15-cycling-a-planted-aquarium/): Cycling a planted aquarium is tricky. If the plants start growing from the get-go the plants can absorb the ammonia before the beneficial bacteria can get to it. Now, this isn’t completely detrimental. The plants will simply act in place of the beneficial bacteria, and all will be well. There will be short spikes of - [12.10. The Shotgun Approach](https://aquariumscience.org/12-10-the-shotgun-approach/): Many times, fish keepers get a pathogen in their aquarium which defies diagnosis. They are doing everything right and fish are still dying. Their water is well filtered and crystal clear. There are no bacteria in the water column. Their aeration is great. And yet their fish are dying with no apparent symptoms. This is - [12.9. Avoiding Disease](https://aquariumscience.org/12-9-avoiding-disease/): The best preventative for fish diseases is to have water which is heavily biofiltered, bacteria free and crystal clear. The key question all needs to ask is: “If one looks down the length of the aquarium though the water, are objects at the far end of the aquarium crystal clear? Does it look like everything - [10.16. Graphite Disease in Bettas](https://aquariumscience.org/10-16-graphite-disease-in-bettas/): There is a disease of blue or black bettas where the fish has fins which disintegrate and/or gets dark metallic gray patches on its body. The key point here is the name "GRAPHITE". This is called “graphite disease” because it looks just like dark gray metallic graphite. Here is what graphite looks like: The well-intentioned - [10.3.10. Red Mouth in Goldfish](https://aquariumscience.org/10-3-10-red-mouth-in-goldfish/): There is a bacterial disease which causes a red mouth in goldfish called enteric red mouth disease. This bacterial infection can cause subcutaneous hemorrhage that presents as reddening of the throat, mouth, gill tips, and fins, and eventual erosion of the jaw and palate. Hemorrhaging also occurs on internal organs, and in the later stages - [11.18. Black Head Syndrome](https://aquariumscience.org/11-18-black-head-syndrome/): There is a symptom which is very disconcerting to the fish owner but typically relatively harmless. The fish will have a very clearly defined part of its body turn black. Often the discoloration is only on one side of the head. It might then turn back to normal coloration in a day or it might - [15.6.4. CO2 From Food](https://aquariumscience.org/15-6-4-co2-from-food/): There is one "interesting" approach to providing carbon dioxide to the aquarium which bears mentioning. This is to use food as the source of CO2. Note I do NOT recommend this method. It is challenging, to say the least. Let’s do some simple math here. In a planted aquarium it is desirable to add VERY - [11.3. Malawi Bloat](https://aquariumscience.org/11-3-malawi-bloat/): Cichlid fish from Lake Malawi in Africa (“African Cichlids”) often get very swollen in the belly. This is the infamous “Malawi Bloat”. But it should be noted that “bloat” is seen in Cichlids not from Lake Malawi. Dropsy and Bloat Dropsy and bloat are two conditions seen often in fish. Both mean a fish which - [15.6.3. High Tech CO2 Systems  ](https://aquariumscience.org/15-6-3-high-tech-co2-systems/): Most high-tech planted aquariums use a high-tech CO2 injection system. These systems are prone to failures, and I don’t recommend them for aquariums with decent numbers of decent sized fish. And this is one case where cheaper can get you into trouble. It is often more difficult to set up cheaper high tech pressurized systems - [15.6.2. KH pH CO2 Relationships](https://aquariumscience.org/15-6-2-kh-ph-co2-relationships/): The relationship of CO2, pH and dKH levels is called the "Bermuda Triangle" of aquarium chemistry with good reason. It is very complex and making simplistic assumptions about it can easily lead one astray and kill fish. If one is a real nerd, like the author, read on, just be prepared to get very confused - [8.7.7. Bottom of the Tank Matten](https://aquariumscience.org/8-7-7-bottom-of-the-tank-matten/): This is an idea one “Gardenman” on the Aquarium Co-op Forum came up with. He put the plates and lifts of two undergravel filters into two aquariums. He then covered the plates with two inches of 40 ppi charcoal colored foam. He put an air stone in one of the lifts and a powerhead on - [16.13. A Few Oddities](https://aquariumscience.org/16-13-a-few-oddities/): There are several things mistaken for "algae" or "fungus" which are not. This includes the water molds and slime molds covered in these links: 16.10. Water Molds 16.11. Slime Molds But there are a few even rarer types of oddities often mistaken for "algae". These include fissidens moss, black pellia, bryozoans and sponges. Fissidens Moss - [97. Author](https://aquariumscience.org/97-author/): 1 Basics, 2 Cycling, 3 Food, 4 Water, 5 Toxins, 6 Filtration, 7 Media, 8 Filters, 9 Aeration, 10 Diseases, 11 Symptoms, 12 Treatment, 13 Stocking, 14 Equipment, 15 Plants, 16 Algae, 17 Fish, 18 Maintenance The author, David Bogert (LaBelle, Florida), has kept many aquariums of all sorts and fish of all sorts for over 56 years. But note he is NOT an "expert" on ANY - [15.13. Hau Planted Aquariums](https://aquariumscience.org/15-13-hau-planted-aquariums/): There is a tiny fish store called "Ocean Aquarium" in an alley in the Tenderloin district of San Francisco run by one Justin Hau. He is a very good innovator and designer of cheap, DIY aquarium systems for planted aquariums. He is extremely knowledgeable and freely shares his knowledge with all who come to his - [15.6.1. Low Tech CO2](https://aquariumscience.org/15-6-1-low-tech-co2/): There are two low tech CO2 systems extant. One, an inverted bottle diffuser, is for ONLY small low tech tanks under 20 gallons (80 liters). The second, a "wide mouthed jar" diffuser, will work well for much larger aquariums. These type systems are often called "passive CO2 bottles". Bottle Diffuser for Small Aquariums There is - [16.2.6. Chemical Algae Control](https://aquariumscience.org/16-2-6-chemical-algae-control/): We do not recommend chemicals to treat algae. The two photos above were posted to an aquarium forum in Facebook. The show what API Algaefix did to a tank. It killed every fish. This is VERY common. Any chemicals (save antibiotics for "blue green algae") which kill algae are "disinfectants" that will kill ANY cell - [16.2.5. The Algae War](https://aquariumscience.org/16-2-5-the-algae-war/): Summary This is only for planted aquariums. If you have a fish only aquarium ignore this article. It is very important to plant a planted aquarium with a LOT of plants. There needs to be a plant of some sort every three inches. To illustrate, a 20 gallon aquarium is 24 x 12 x 16. - [16.2.4. Algae Eaters](https://aquariumscience.org/16-2-4-algae-eaters/): A very good way to treat nuisance algae in the aquarium is by using "algae eaters". These include sucker catfish such as bristlenose catfish (ancistrus), otocinclus, flying foxes (Epalzeorhynchos kalopterus), Silver Flying Fox (Crossocheilus reticulates) and Siamese algae eaters (Crossocheilus siamensis). Black mollies, hillstream loaches and redline sharks also eat algae. Shrimp and snails also - [16.2.3. Algae in Low Tech Tanks](https://aquariumscience.org/16-2-3-algae-in-low-tech-tanks/): By the terms "low tech planted aquarium" we mean an aquarium with vascular plants but no carbon dioxide injection. In these types of planted aquariums heavy algae growth can be prevented by several means: Have a LOT of vascular plants Somehow add enough carbon dioxide to get the CO2 level up to at least 10 - [16.2.2. Algae in High Tech Tanks](https://aquariumscience.org/16-2-2-algae-in-high-tech-tanks/): We define a "high tech planted aquarium" as a planted tank with carbon dioxide injection and high intensity lighting with some crimson and blue light. There are a whole list of things needed for the good growth of higher plants in the high tech planted aquarium: One plant every three inches across the whole aquarium - [16.2.1. Algae in Fish Only Tanks](https://aquariumscience.org/16-2-1-algae-in-fish-only-tanks/): To control a severe algae outbreak in a fish only aquarium it is best to simply do some six to eight 50% water changes over the span of two days. Contrary to popular mythology, large water changes are perfectly natural (a fish swimming in a river has a water change every second) and harmless to - [15.12. Propagating Plants](https://aquariumscience.org/15-12-propagating-plants/): To have a good well planted aquarium it is necessary to have a LOT of THRIVING plants. These thriving plants put out chemicals which control algae quite effectively. But a few plants here and there in an aquarium typically will simply not do well. For an example let's take a sixty-gallon aquarium. Let us add - [18.5. Heavy Stocked Maintenance](https://aquariumscience.org/18-5-heavy-stocked-maintenance/): Probably 95% of all aquariums in the hobby are just fine with just a very easy maintenance regimen. But if one looks up stocking ratio apps and websites and does the inputs into those sites AND those sites say you are over 100% stocked or over, i.e. overstocked, one CAN have a problem. ONLY if - [15.5.3. Estimative Index](https://aquariumscience.org/15-5-3-estimative-index/): The Estimative Index (EI) method is the most popular method of dosing fertilizers in high-tech planted CO2 injected aquariums. I find it to be somewhat complicated and very time-consuming to implement. But there is no question it will give one a very beautiful high-tech planted aquarium. Most of the data on the Estimative Index will - [15.10. Hybrid Planted Aquariums](https://aquariumscience.org/15-10-hybrid-planted-aquariums/): This article is about a type of planted aquarium where the "low tech" CO2 system is to obtain the CO2 from wood pellets buried in the substrate rather than getting the CO2 from some CO2 gas system. The system uses chemical fertilization. So this is sort of a "hybrid" between low tech and high tech - [18.4. Cleaning a Filter](https://aquariumscience.org/18-4-cleaning-a-filter/): This is a duplicated article. It is so important I thought I should put it on the website twice. Both beginners and experienced aquarium owners often make a big mistake which stresses fish in their aquarium. They give their new filters a thorough cleaning at the end of cycling. Or they clean their filters thoroughly - [18.3. Cleaning the Substrate](https://aquariumscience.org/18-3-cleaning-the-substrate/): There are a host of YouTube videos emphasizing that it is essential to "deep clean" and "deep vacuum" the substrate of an aquarium at least once a week. We do NOT recommend doing this. "Deep cleaning" the substrate can be difficult and is very time consuming. And it has NO positive effect on the health - [18.2. Drip Water Changes](https://aquariumscience.org/18-2-drip-water-changes/): A continuous drip water change system uses permanent plumbing to continuously and automatically change the water in one or more aquariums via a 24/7 drip. Drip water systems require two pipes into the aquarium area. One line of pipe comes from a water supply such as a municipal water supply or a well and supplies - [18.1.3. Water Change Water](https://aquariumscience.org/18-1-3-water-change-water/): Newcomers to the hobby are bombarded in the fish store with all sorts of water treatments: conditioners, stress coat, pH adjusters, ammonia detoxifier, bacteria in a bottle, buffers, aquarium salt, ad. infinitum. Only a cheap conditioner is necessary. All the other products are simply scams. When it comes to water this is the “Rule” . - [18.1.2. Aquarium Water Change Math](https://aquariumscience.org/18-1-2-aquarium-water-change-math/): There is a “rule” that says you need to change the water 50% every week and a 25% change twice a week with an aquarium. The only reason for doing water changes is to keep the nitrates down. Note there are all sorts of other reasons given on social media for doing water changes: "You - [18.1.1. Water Changes in Depth](https://aquariumscience.org/18-1-1-water-changes-in-depth/): It is generally (but not universally!) accepted that fish will do better in an aquarium if some of the water is drained upon occasion and replaced with new clean water. This is called a “water change”. People drain and refill anywhere from 75% of the aquarium twice a week to 10% of the aquarium every - [18.1. Aquarium Water Changes](https://aquariumscience.org/18-1-aquarium-water-changes/): It is generally (but not universally!) accepted that fish will do better in an aquarium if some of the water is drained upon occasion and replaced with new clean water. This is called a “water change”. People drain and refill anywhere from 75% of the aquarium twice a week to 10% of the aquarium every - [18. Aquarium Maintenance](https://aquariumscience.org/18-aquarium-maintenance/): Typically people do maintenance on their aquariums at some set time interval. Some do it every week. And some do it every two months. There typically are several items which make up maintenance. Water changes make up the bulk of time spent in aquarium maintenance. Many clean the gravel every water change, something I do - [15.5.4. NH4 and Tabs Fertilizer](https://aquariumscience.org/15-5-4-nh4-and-tabs-fertilizer/): What follows is a guide to making a series of do-it-yourself (DIY) fertilizers for aquariums that are the preferred fertilizers for the author. The author prefers ammonium based fertilizers that put the iron and phosphorus into the plants in the form of root tabs. It is followed by some data on the chemicals for fertilizing - [15.6.5. Liquid CO2](https://aquariumscience.org/15-6-5-liquid-co2/): There are a whole series of products which supposedly add "liquid carbon" to a planted aquarium. There are three points which summarize the discussion: "Liquid carbon" does preferentially kill algae over vascular plants because the cell walls of algae are thinner than the cell walls of vascular plants. Since the cell walls of a fish's - [15.5.1. Ready Made Fertilizers](https://aquariumscience.org/15-5-1-ready-made-fertilizers/): The easiest approach to planted aquarium fertilizing is to simply use Aquarium Co-Op Easy Green™ per the instructions on the container. Easy. Simple. Reasonably effective but expensive. For a far more in-depth and very boring analysis of this ready made fertilizer and similar products read on. Preprepared Fertilizers There are two distinct types of preprepared - [15.11. Many Fish Many Plants](https://aquariumscience.org/15-11-many-fish-many-plants/): It is difficult to have a well planted tank with a lot of sizable fish. The fish require aeration to do well and the plants do not like aeration as it depletes the water of the carbon dioxide the plants require. Plants like a CO2 level above 10 ppm. At equilibrium with the atmosphere pure - [15.9. High Tech Planted Aquariums](https://aquariumscience.org/15-9-high-tech-planted-aquariums/): I define a "high tech planted aquarium" as an aquarium with CO2 gas injection to at least 20 ppm and high intensity LED lighting with blue and crimson components ("grow lights"). In general, high tech planted aquariums have the following characteristics: Note this is ONLY a TYPICAL set up. None of these parameters are cast - [15.8. Walstad Aquarium](https://aquariumscience.org/15-8-walstad-aquarium/): Diana Walstad wrote the “bible” on “low tech” planted tanks. Her book is called “The Ecology of the Planted Aquarium”. If one wants to know this topic in depth from a true expert, I heartily recommend this book (I think I’ve probably read it about five times!). She is the ONLY aquarium book author that - [10.4.2. Mycobacteriosis in Humans](https://aquariumscience.org/10-4-2-mycobacteriosis-in-humans/): All home hobbyists should be aware that Mycobacterium marinum (the bacteria responsible for most cases of "fish TB") can infect humans. It typically presents in humans as a very slowly developing (weeks or months) lesion which looks like a big pimple, abscess or carbuncle. A good YouTube video on this subject can be found at - [2.14. The Mature Aquarium](https://aquariumscience.org/2-14-the-mature-aquarium/): A "mature aquarium" (sometimes called a "seasoned aquarium" or a "balanced aquarium") is an aquarium with a lot of diversity in the brown gunk in its filter, tank, and substrate. In a mature tank this brown gunk is full of tiny little organisms which are carnivores, eating other tiny organisms and food stuffs, including disease - [14.13. Aquarium Electric Cost](https://aquariumscience.org/14-13-aquarium-electric-cost/): Summary If you are taking the temperature of the aquarium up ten degrees F (5.60 C.) most setups will cost you roughly $1.50 per month for every ten gallons (38 liters), priced as of 2018. That is for filter, lights, and heater. This figure came from a commentator on this website who put a wattage - [7.6. Media Surface Area](https://aquariumscience.org/7-6-media-surface-area/): References on Ammonia and Surface Area If one is only concerned with ammonia oxidation, as little as five square feet of static submerged biomedia surface per metabolic pound of fish can be used to produce safe levels of ammonia and nitrite for tropical fish. A reference is useful here: “Simply put, if you do a - [14.2.2. Gravel](https://aquariumscience.org/14-2-2-gravel/): My recommendation is “natural” aquarium gravel, such as the picture above. The cream through brown varied color hides accumulated detritus and feces. Mono-colored substrate such white gravel simply look really bad when fish poop, which is something fish do ALL the time. Small gravel, such as the 3-6 millimeter colored gravel sold in most aquarium - [17.11. Discus](https://aquariumscience.org/17-11-discus/): Discus are probably the most beautiful fish in the freshwater aquarium trade. The advantages of discus are: Gorgeous fish with many color variations Slow moving and "dignified" in their manner Long-lived. I have a friend that swears he has a twenty-five year old discus One of the few cichlids that do well with plants Males - [16.10.1. White Fuzz](https://aquariumscience.org/16-10-1-white-fuzz/): There are a whole host of ways in which water molds and other “white” organisms can present in the aquarium. The terms for such “fuzz” include fungus, mold, slime, tufts, coating, cotton, white streamers, fog etc. Most of these white fuzzy growths are species of “water mold” (order Saprolegniales, generally from three genera: Achlya, Leptolegnia, - [2.8.2. Sludge Removing Bacteria](https://aquariumscience.org/2-8-2-sludge-removing-bacteria/): There are products which are supposedly "sludge removing" bacteria-in-a-bottle. These include Seachem Pristinetm, Tetra Cleaning Bacteriatm, API Stresszyme +tm, Fluval Biological Cleanertm, Nutrafin Waste Controltm , Outbreak!tm, FritzZyme® MONSTER 360tm and Dr. Tim's Waste Awaytm. They are the very definition of fraud. . “Definition of fraud; DECEIT, TRICKERY, specifically: intentional perversion of truth in order - [10.15. Dwarf Gourami Disease](https://aquariumscience.org/10-15-dwarf-gourami-disease/): A comment to this page is helpful here: "We have just lost six out of seven dwarf gouramis. They all died over the course of 3 weeks with some going very quickly and others dying slowly. I expect the last one to go any day now. It is such a shame as they are beautiful - [16.12. Red Spot Algae](https://aquariumscience.org/16-12-red-spot-algae/): Red spot algae is a type of red algae (rhodophyta) that forms bright reddish brown circles on the glass and red coatings on the leaves of plants. It clings very tenaciously to everything. It can take determined scrubbing to remove it. It is relatively slow growing. It generally comes with high nitrates or high iron. - [17.10. Aquarium Shrimp](https://aquariumscience.org/17-10-aquarium-shrimp/): Many people get small shrimp as additions to their aquariums. They buy the shrimp and throw them in a newly set up tank. The shrimp then die. Or they put the shrimp in with larger fish who eat the shrimp when the shrimp do something called “molting” (after molting the exoskeleton of the shrimp is - [15.7. Plant Substrates](https://aquariumscience.org/15-7-plant-substrates/): Plant Substrates in a Nutshell Most aquarium plants grow in pretty much any aquarium substrate. Let me emphasize that point; . Most aquarium plants grow in pretty much any aquarium substrate . Mother Nature is just very forgiving. This makes things very confusing for the beginner. They watch one YouTube video where the video - [4.5.2.1. KH and Cycling](https://aquariumscience.org/4-5-2-1-kh-and-cycling/): Carbonate hardness (KH) is important for nitrifying bacteria. For every 10 ppm of ammonia converted to nitrate very roughly 71.4 ppm (71.4 KH or 4 dKH) of carbonate is used up. Each gram of most ammonium salts requires very roughly three grams of sodium bicarbonate (baking soda), A reference is useful: “How Alkalinity Affects Nitrification”, - [4.8.1. Rapid Thermal and pH Shifts](https://aquariumscience.org/4-8-1-rapid-thermal-and-ph-shifts/): The going mantra is that tropical fish require "stability" and “constancy” of pH and temperature. Supposedly any rapid change over 0.2 pH or 2 degrees temperature will “shock”, “stress” and possibly kill the fish. This idea is a myth. Experimentation and scientific research by the author and universities has shown this to be patently false. - [4.10. ORP or Redox](https://aquariumscience.org/4-10-orp-or-redox/): ORP stands for “Oxidation Reduction Potential” while Redox stands for “Reduction/Oxidation.” These two terms are interchangeable. Both refer to a process in which one chemical substance is reduced and another chemical substance is oxidized. For instance, when coal burns in air, the coal is oxidized and the oxygen in the air is reduced. ORP (or - [10.2.2.7. Ich and Heat](https://aquariumscience.org/10-2-2-7-ich-and-heat/): Ich and Raising the Temperature Ich simply is not normally fatal in ANY aquarium with an established filter because the established filter stops the ich organism. An established filter has a whole host of tiny, microscopic organisms on the surface of the filter media which can trap and literally eat the infectious ich theront. The - [5.5.3.5. Conditioner Testing](https://aquariumscience.org/5-5-3-5-conditioner-testing/): A simple test was set up. In order to get better accuracy the level of chlorine (sodium hypochlorite bleach) was taken to four times the "normal" amount in tap water. Chlorine was added to a gallon of distilled water at the level of 4 ppm. Then the following water conditioners were added to cups of - [5.5.3.4. Cost of Conditioners](https://aquariumscience.org/5-5-3-4-cost-of-conditioners/): My recommendation with conditioners is simple: . Buy ONLY Conditioners that say "Sodium Thiosulfate" on the Bottle in the Ingredients List. Then use 5X the Recommended Dosage. . When I used to have chlorinated water for a 60 gallon tank 50% water change I would first off leave the fish in the aquarium. I would - [5.5.3.3. Conditioner Chemistry](https://aquariumscience.org/5-5-3-3-conditioner-chemistry/): All conditioner's use the same basic chemistry to do the same thing. They all have some form of a sulfite (SO3, one sulfur atom with three oxygen atoms) that oxidizes in the presence of chlorine to a sulfate (SO4, one sulfur atom and four oxygen atoms). The reaction turns the toxic chlorine into harmless table - [8.9.3. Assimilatory Denitrification](https://aquariumscience.org/8-9-3-assimilatory-denitrification/): Removing Nitrates with Assimilatory Denitrification Bacteria, fungi, water molds, wood, algae, mulm, protozoa, plants and, indirectly, fish can absorb nitrates, nitrites and ammonia from the water and produce proteins. This can reduce the nitrogen compounds by something called "assimilatory denitrification". It is common and well documented. It is relatively common for an aquarium to have - [7.1.3.1. Ammonia Oxidizing Test](https://aquariumscience.org/7-1-3-1-ammonia-oxidizing-test/): A test of the ammonia oxidizing capability of ten different filter media was undertaken. Ceramic rings, lava rock and BioHome were the worst media. Bioballs and Matrix were twice as good as the rings. Aquarium gravel and Matala pads were three times as efficient as the rings. Static K1 media and pot scrubbers were five - [6.5.2. Substrate as a Filter](https://aquariumscience.org/6-5-2-substrate-as-a-filter/): Two tests were run, both of which showed that the substrate in an aquarium does little in the way of biofiltration. Each of the tests was run as a “side test” to tests of filters. Abstract A test of the ammonia oxidizing capability of one inch of gravel substrate was set up and tested. This - [6.8.1. Filter Cleaning Tests](https://aquariumscience.org/6-8-1-filter-cleaning-tests/): Abstract Multiple replicate scientific experiments were carried out with controls. These studies looked at cleaning sponge filters. They established that: Cleaning a newly established (months) sponge filter under RUNNING unchlorinated well water or RUNNING chlorinated water removed virtually all the beneficial bacteria Cleaning a newly established (months) sponge filter by VERY LIGHTLY SWISHING back and - [2.4.1. Dr. Tim’s Cycling Method](https://aquariumscience.org/2-4-1-dr-tims-cycling-method/): One of the more popular methods of cycling is to use Dr. Tim's ammonia solution. We do not agree with the methods of Dr. Tim but his method will work. It will just result in an aquarium that cannot handle very many fish in the beginning. Here is an analysis of Dr. Tim's method: Dr. - [3.9. Fish Food and Gunk](https://aquariumscience.org/3-9-fish-food-and-gunk/): There is an interesting relationship which occurs in fish only aquariums. The amount of brown gunk, beneficial bacteria and nitrate produced in a filter media is dependent on the ratio of carbon to nitrogen in the food. With higher carbon to nitrogen ratios there is LESS BENEFICIAL BACTERIA PRODUCED, more "bad" heterotrophic bacteria produced in - [12.8. Euthanizing a Fish](https://aquariumscience.org/12-8-euthanizing-a-fish/): What is the most humane way to euthanize aquarium fish? Sometimes fish are just too far gone, and people want to humanely kill them. There is nothing wrong with that but there are many PETA folks on social media who will blast anyone considering humanely euthanizing a fish. That is just the way social media - [7.1.3.2. Water Clarity Test](https://aquariumscience.org/7-1-3-2-water-clarity-test/): Testing Aquarium Filter Media for Effect on Water Clarity Abstract Clarity of the water was measured for ten 40 gallon aquariums with different filter media in canister filters and a heavy load of food. Four tests were run totaling some thirty aquarium and canister filters for some three months each. The second test used half - [2.8.1. Bacteria in a Bottle in Depth](https://aquariumscience.org/2-8-1-bacteria-in-a-bottle-in-depth/): We tested bacteria in a bottle products and found they simply didn't work "as advertised". This is an in-depth analysis of this test and the test procedure. It is very long and very boring and only for the folks who are nerds like the author. Other Tests There will always be those doubters who say - [5.5.3.2.5. Prime Concentration](https://aquariumscience.org/5-5-3-2-5-prime-concentration/): Seachem makes two water conditioners, Prime and Safe. They make a series of claims about these two products which are simply snake oil marketing hype. This article examines one of those claims. . False claim #5, Prime is 5x More Concentrated Than Competing Products . In their literature Seachem claims that Prime is 5X - [5.5.3.2.6. Safe Cannot be Made into Prime](https://aquariumscience.org/5-5-3-2-6-safe-cannot-be-made-into-prime/): Seachem makes two water conditioners, Prime and Safe. Seachem also makes a series of marketing claims for these products which are pure hogwash. This article examines one of those claims. . False claim #6, Safe Cannot be Made into Prime. . Since both Safe and Prime are simply sodium dithionite, the idea that Safe cannot - [5.5.3.2.4. Prime, Safe and Chloramine](https://aquariumscience.org/5-5-3-2-4-prime-safe-and-chloramine/): Seachem makes two water conditioners, Safe and Prime. Both these products make a series of claims which are just plain false. In a letter, the Seachem lawyer made a false claim which this article examines in depth: . False claim #4, Only Prime and Safe Remove Chloramine . In the Seachem lawyer's letter in - [5.5.3.2.3. Prime, Safe and Sodium Dithionite](https://aquariumscience.org/5-5-3-2-3-prime-safe-and-sodium-dithionite/): 5.5.3.2.3. Prime, Safe and Sodium Dithionite Prime and Safe are two water conditioners made by Seachem. The Seachem marketing department makes a series of claims about these two products which simply are not true. This article examines one of those claims. Note that I admit I am decidedly biased against the Seachem Company. I can't - [5.5.3.2.2. Prime, Safe and Cycling](https://aquariumscience.org/5-5-3-2-2-prime-safe-and-cycling/): Prime and Safe are two water conditioners made by Seachem. The marketing department at Seachem has made a series of false marketing claims for these two products. This article examines one of those claims. Note that I admit I am decidedly biased against the Seachem Company. I can't help it. The amount of "pseudoscientific bedazzlement" - [5.5.3.2.1. Prime, Safe and Ammonia](https://aquariumscience.org/5-5-3-2-1-prime-safe-and-ammonia/): Synopsis The simple conclusion of this article is simply that no less than TEN tests done by three qualified scientists conclusively show that Seachem Prime does NO "detoxification" or "binding" of ammonia, not even on a temporary basis. Seachem has ZERO tests which prove Prime detoxifies ammonia. That is correct, ZERO tests. Seachem also claims - [2.5.1. Fish-in Cycling Science](https://aquariumscience.org/2-5-1-fish-in-cycling-science/): Fish in Cycling can VERY RARELY Kill Fish The PETA folks and other well-meaning hobbyists will rail against "fish-in cycling" as being "mean and cruel". They say fish-in cycling will hurt, damage, or even kill the fish. They have a point in certain rare cases. If beginners in the hobby know enough to only put - [17.5.4. Goldfish Care](https://aquariumscience.org/17-5-4-goldfish-care/): Goldfish Care The common narrow bodied goldfish are simply the easiest fish there is to keep due to hundreds of years of "inadvertent selective breeding". Yet well meaning but ill-informed individuals on social media will tell the hobbyist that goldfish are very touchy fish that requires a great deal of careful care. This is because of - [17.5.3. Stocking Goldfish](https://aquariumscience.org/17-5-3-stocking-goldfish/): Stocking for goldfish (i.e. the number of gallons needed for each goldfish) is controversial, to put it mildly. But it all can be summarized in one bullet: . It all boils down to an OPINION . It is the OPINION of many hobbyists that goldfish need very large aquariums in order to "thrive". It is - [17.5.2. Size of Goldfish](https://aquariumscience.org/17-5-2-size-of-goldfish/): Goldfish Size In a Nutshell In a small aquarium a common goldfish will grow to possibly four inches and no greater. In a large lake a common goldfish will normally grow to six inches with an occasional fish getting to eight inches. If you want a bit of a rant followed by a very long - [17.5.1. Types of Goldfish](https://aquariumscience.org/17-5-1-types-of-goldfish/): There are two distinct types of goldfish. The common, sarasa and shubunkin goldfish are one type of goldfish, which some call "narrow bodied goldfish". These fish are easily kept under many different conditions, including overcrowded, small tanks with poor water quality. They can live to be 20 or even 30 years old. “Fancy goldfish” or - [3.1.1. Fish Food Science](https://aquariumscience.org/3-1-1-fish-food-science/): A Caveat Protein Level in the Food The most important variable when choosing a fish food is the protein level. The higher the protein level in any food the healthier the fish. But this effect is NOT because eating high protein food is good for a fish. Rather the effect is due to what high - [2.13. Cycling Test](https://aquariumscience.org/2-13-cycling-test/): A series of tests were run in buckets to see what feeding regimes produced the fastest cycles. The second series of tests were run in the buckets to see what water parameters give the best cycling times. A caveat has to be noted here. These tests were run in the same room that held several - [4.5.2. Carbonate Hardness](https://aquariumscience.org/4-5-2-carbonate-hardness/): Carbonate Hardness "Carbonate hardness" or "KH" is a confusing term because it does not refer directly to what most people associate with the term "hardness". "Hard water" is normally thought of as high GH water which can be so "hard" it creates "hard" deposits in water lines. These "hard" deposits what the term "hardness" is - [8.1.1. Filter Test](https://aquariumscience.org/8-1-1-filter-test/): How "Good" is a Filter? What must be emphasized here is that most people key in on only ammonia and nitrite oxidation when looking at a filter. For instance, if a hang-on-back cartridge filter gives zero ammonia and zero nitrite then you see comments like "the hang-on-back cartridge works fine". Ammonia and nitrite oxidation require - [17.9. Nano Aquarium](https://aquariumscience.org/17-9-nano-aquarium/): "Nano aquariums" are simply small aquariums. There are very roughly two different "nano aquariums" in the hobby. One is under five gallons in size and one is from five to fifteen gallons. They will be treated separately. Under Five Gallon "Nano" Aquarium One special situation is when someone has a small one half to five - [17.8 Oscars](https://aquariumscience.org/17-8-oscars/): Oscars are a special fish. As anyone who has kept Oscars can tell you, they are a very intelligent fish with distinct "personalities". The author had one Oscar that would kill anything put in his tank, literally. He killed a Jack Dempsey that was bigger than he was. A Siamese cat accidently fell into this - [11.17. Black Death](https://aquariumscience.org/11-17-black-death/): Black Death, also called "discus plague", is where the fish turns very dark, almost black. The fish will typically (but not always!) exhibit slime coat syndrome, where the mucus on the skin of the fish becomes thick and sloughs off. The fish will become reclusive, huddling in a dark corner of the tank. This syndrome - [12.7. Making Medicated Food](https://aquariumscience.org/12-7-making-medicated-food/): To treat internal diseases of tropical fish’s it is necessary to make special food. The manufacturers of fish medications for internal diseases make a huge amount of money by recommending that one put the medication in the water but it simply doesn't work. To further explain this go to this article: 12.5. Fish do not - [1.1.13. Aquarium Fish Selection](https://aquariumscience.org/1-1-13-aquarium-fish-selection/): Beginner Fish As for the selection of fish for a beginner, some fish are quite accepting of the mistakes we all make as beginners to the hobby. These fish are: All types of Glofish (Kids love them) Platy Endler Livebearer Red Eye*, Black Phantom*, Black Neon* and Black Tetras* Harlequin Rasbora* White Cloud Mountain Minnow - [1.4.1. Facebook Fake Accounts](https://aquariumscience.org/1-4-1-facebook-fake-accounts/): There are hundreds of thousands of Facebook followers on aquarium forums and groups. A huge number of newcomers to the hobby come on social media and join these forums and groups in order to get information. This is a goldmine which aquarium supply manufacturers cannot resist. So they have done a number of, shall we - [10.14. Fish Lice](https://aquariumscience.org/10-14-fish-lice/): Fish lice are Argulus, a crustacean. These are rarely seen if tropical fish, but they can occur, especially in pond raised fish. Since true lice are insects the term "fish lice" is a misnomer. There are several varieties of fish louse, including a very transparent one which is hard to see on the fish. Fish - [8.3.3. FX Series Canister Filters](https://aquariumscience.org/8-3-3-fx-series-canister-filters/): FX Canister Aquarium Filters The Fluval FX series of canister filters can either be very poor biological filters or a very good biological filters: If you follow the Fluval directions and clean the foam once a month the FX filters will be very poor biological filters. If you only clean the foam lightly every six - [4.4.5. Raising pH](https://aquariumscience.org/4-4-5-raising-ph/): Sometimes aquarium water out of the faucet that has set for two days has a pH less than 6.5 and needs to be raised. This is common in New England. A pH of 6.5 will reduce the growth of beneficial bacteria by 90%. A pH of 6.0 will virtually stop beneficial bacteria from oxidizing ammonia - [4.4.4. Dropping pH](https://aquariumscience.org/4-4-4-dropping-ph/): Newcomers constantly ask on social media "How do I get my pH down for my fish?". First off, if the pH is below 8.5 you typically don't need to bring it down for most fish. Even black water Amazonian fish do well at anything lower than 8.5 pH. If you have an aquarium with a - [10.2.6. Tetrahymena](https://aquariumscience.org/10-2-6-tetrahymena/): Tetrahymena is a single celled ciliated protozoan closely related to paramecium and epistylis. It can be found in the detritus of most aquariums. It can be very similar in appearance on the fish to columnaris, ich and epistylis. Like epistylis, tetrahymena is found in the detritus of most aquariums and feeds on bacteria in the - [10.13.4. Aquarium Leeches](https://aquariumscience.org/10-13-4-aquarium-leeches/): Leeches are interesting little critters sometimes seen in aquariums. They are annelid worms or "tubeworms" closely related to good old earthworms. There are several varieties seen in aquariums. The most common are snail leeches and Asian leeches. They all have a round body which typically remains motionless and a thinner head that waves about hunting - [8.7.6. Small Filters](https://aquariumscience.org/8-7-6-small-filters/): Let me make one thing very clear: . SMALL filters do decent filtration in SMALL aquariums with SMALL numbers of SMALL fish . Do not put a small filter in a 30 gallon tank with five angelfish, three pearl gouramis and five swordtails and expect to have an ammonia free aquarium with crystal clear water. - [6.9. Tap Water Rinsing](https://aquariumscience.org/6-9-tap-water-rinsing/): There is the constant myth on social media that one needs to clean the filters and filter media in tank water to prevent the chlorine in tap water from removing and killing all the beneficial bacteria. This is simply a false myth. Synopsis of Test Multiple replicate scientific experiments were carried out with controls. These - [17.6. Guppies and Livebearers](https://aquariumscience.org/17-6-guppies-and-livebearers/): This is an article about what are called "livebearers". These are fish which bear their young alive. This includes guppies, platies, mollies and swordtails. All livebearers have two common diseases: capillaria, an intestinal worm which typically manifests itself as hollow belly, arched back, wasting, spitting out food and intestines popping out. tetrahymena, a small skin - [5.5.3.2. Prime and Safe](https://aquariumscience.org/5-5-3-2-prime-and-safe/): Conclusions Six Articles prove six points (click on the article to read it) Article # 1, Prime and Safe do NOT detoxify ammonia, nitrite, and nitrate. Article #2, Prime and Safe used during cycling lengthens the cycle time. Article #3, Prime and Safe are both sodium dithionite Article #4, All conditioners are equally effective with - [1.1.1. The First Aquarium](https://aquariumscience.org/1-1-1-the-first-aquarium/): You're going to buy an aquarium! So you go to Walmart and you buy a ten-gallon aquarium kit. Now, what do you do? The kit comes with: A ten-gallon aquarium A LED light An in-tank cartridge filter Some food A water conditioner Ignore the directions that come with the aquarium and the directions that you - [1.1.12. How to Make Fish Thrive](https://aquariumscience.org/1-1-12-how-to-make-fish-thrive/): There was some aquarium advice on Facebook from one Sean Dwyer which I think was excellent: "Have fun Watch your fish behavior so you can tell if something is off Don't stress and overthink anything. Keeping the hobby enjoyable is most important. If you don't enjoy what you are doing, the fish will suffer more - [1.1.11. Ich](https://aquariumscience.org/1-1-11-ich/): Fish in a newly set up aquarium often get little white spots all over their bodies. This is a disease called "ich" or "white spots". Treating ich is very easy. Just use formalin/malachite green (Ich-X, Rid-Ich Plus, Blue Planet White Spot Remedy, and Mardel QuickCure) to treat ich in freshwater fish. Below I get into - [1.1.9. "Brown Algae"](https://aquariumscience.org/1-1-9-brown-algae/): If you are a newcomer to the hobby just accept the fact that brown algae will form in the aquarium and just leave it be in the aquarium. Do NOT try and fight the brown algae. It is a war the algae will win. Brown Algae in More Depth Newcomers to the hobby who set - [1.1.8. Stocking](https://aquariumscience.org/1-1-8-stocking/): The number of fish and the size of the fish in an aquarium is called the "stocking" of an aquarium. Any beginner to the hobby should start with a few fish under three inches in size and gradually increase either the size or the number of fish in the aquarium over the span of at - [1.1.7. Aeration](https://aquariumscience.org/1-1-7-aeration/): One of the five keys to any healthy aquarium is aeration. In an aquarium with even moderate amounts of fish, aeration is essential for healthy fish. The aeration not only keeps the fish healthy, but it also keeps the beneficial bacterial populations healthy. Aeration can be accomplished either by lots of air bubbles from an - [1.1.5. Filters](https://aquariumscience.org/1-1-5-filters/): One Big Scam Any discussion of ANY filter requires a disclaimer. ALL commercial filters almost without exception tell the owner to replace the filter media (cartridges, sponge, ceramic rings, carbon, Matrix, etc.) regularly, once a month, once every three months, or once every six months. Supposedly this is because the media becomes clogged and dirty. - [1.1.6. Filter Media](https://aquariumscience.org/1-1-6-filter-media/): Filter Media Filter media is the stuff inside a filter. It is something that grows beneficial bacteria on its surface These beneficial bacteria remove fish pee (ammonia) from the water. Filter media is important to the health of the fish. The more effective surface area this media has and the less the media is cleaned, - [1.1.4. Water Parameters](https://aquariumscience.org/1-1-4-water-parameters/): The water fish swim in is very important. But it is not nearly as important as people give it credit for. The chemistry of the water, the pH, the hardness, and the salts contained in the water, are just not very important to the well-being of the freshwater tropical fish. . If you can drink - [1.1.3. Fish Food](https://aquariumscience.org/1-1-3-fish-food/): Amount of Fish Food. Overfeeding is one of the chief reasons for fish deaths. What I recommend for feeding is simple; . Feed fish once a day ONLY an amount of food the fish can consume in one minute. . If there is food still in the aquarium after one minute you need to cut - [1.1.2. A Simple Way to Cycle](https://aquariumscience.org/1-1-2-a-simple-way-to-cycle/): “Cycling” is the term used for growing colonies of something called “beneficial bacteria”. These "beneficial bacteria" (defined as both bacteria and archaea) convert toxic fish pee (ammonia) to a relatively innocuous compound called nitrate. Growing these colonies normally takes 4 to 6 weeks. These colonies are the brown gunk that forms on the filter media - [2.9. Instant Cycling Chemicals](https://aquariumscience.org/2-9-instant-cycling-chemicals/): There are a whole series of products that claim to "detoxify" ammonia and nitrite during cycling. They claim these products give an "instant cycle". These claims are simply false marketing hype. Many suppliers of these products write some very lengthy claims and papers on how their products work. They blend scientific fact with fiction to - [6.3. Over-filtration](https://aquariumscience.org/6-3-over-filtration/): Over-filtration is a constant topic on social media and is very misunderstood. For one thing the standard "mythology" is that a tank must have a gallon per hour flow rate that is three to ten times the gallonage of the aquarium. This mythology goes along the lines of a "600 GPH filter will filter twice - [1.5.1. Aquarium Examples](https://aquariumscience.org/1-5-1-aquarium-examples/): A few options for aquariums include: Note if you’re like me you will try each of these types of aquariums over the years you’re in the hobby. Fish keepers seem to like a challenge and then lose interest when they are successful on any given variation. Probably the most far out aquarium I've seen is - [14.10.Wood](https://aquariumscience.org/14-10-wood/): All dead wood, dry or wet, that does not smell like sap is fine just as is in any aquarium. I just throw driftwood or wood from the woods around me into my aquariums and see what happens. Some wood will deteriorate rapidly and smell and must come out. Other wood will last for years. - [5.2.3. High Ammonia](https://aquariumscience.org/5-2-3-high-ammonia/): Most home hobbyists measure the total ammonia via the API "Ammonia" test kit. This test kit measures both ammonia gas and ammonium ions. It is not unusual for a hobbyist to be surprised by a sudden unexpected spike in these numbers. It is not cause for concern most of the time. Ammonia+ammonium spikes and nitrite - [10.12.2. Capillaria](https://aquariumscience.org/10-12-2-capillaria/): A common nematode worm infecting tropical fish is Capillaria worms. These nematodes produce the same symptoms as Camallanus, but they don’t protrude out the anus of the fish. It is often found in necropsies of cichlids which have shown such symptoms as bloat, white poop and not eating. It thus imitates hexamita. Capillaria can also - [10.12.1. Camallanus](https://aquariumscience.org/10-12-1-camallanus/): Camallanus nematode worms are among the most commonly encountered internal parasites for aquarium fish and may infect a wide range of fish species. They are seen as red threads hanging out of the anus of the fish. Camallanus is often found in necropsies of cichlids which have shown such symptoms as bloat, white poop and not - [15.4.1. Planted Aquarium Examples](https://aquariumscience.org/15-4-1-planted-aquarium-examples/): Here are some successful planted aquariums taken off social media. Note how the ones with the healthiest plants are the ones with the least number of fishes. The healthiest planted tanks also almost all have a very heavy planting of plants with little open substrate. The only exceptions to this are a few low tech - [17.4.1. Malawi Aquariums](https://aquariumscience.org/17-4-1-malawi-aquariums/): These are examples of Lake Malawi aquariums pulled off social media. Note that they are all heavily stocked. Heavy stocking is the key to keeping a good Lake Malawi aquarium. This illustrates that Lake Malawi cichlids do best with very heavy stocking. Very heavy stocking reduces aggression. These aquariums all had very good filtration. If - [7.1.3. Filter Media Test](https://aquariumscience.org/7-1-3-filter-media-test/): How "Good" is an Aquarium Filter Media? What has to be emphasized here is that most people key in on only ammonia and nitrite oxidation when looking at filter media. For instance, if a canister filled with lava rock media gives zero ammonia and zero nitrite then you see comments like "the lava rock works - [16.10. Water Mold](https://aquariumscience.org/16-10-water-mold/): "Water mold" (some people incorrectly call it “biofilm”) is very common on wood put in the aquarium. Most aquarium wood will get some of it at some time. "Water mold" can grow very rapidly and appear in days on any piece of wood put into any aquarium. There are about 250 species of “water mold”, - [1.7. Aquarium Slow Fish Deaths](https://aquariumscience.org/1-7-aquarium-slow-fish-deaths/): Condensed Version of "Causes of Slow Death" There are many ways to slowly kill fish in succession. What we do NOT mean by this is when one fish in an aquarium dies. Fish die for unknown causes all the time. Even a fish pathologist who does an "autopsy" on a dead fish will typically be - [1.6. Aquarium Fast Fish Deaths](https://aquariumscience.org/1-6-aquarium-fast-fish-deaths/): There are some things which kill lots of fish rapidly with no symptoms: If the fish died just after a water change: With chlorinated water and a large water change, a chlorine pulse can be to blame (VERY common). With well water and a large water change, low oxygen and/or high carbon dioxide can be - [17.5. Goldfish](https://aquariumscience.org/17-5-goldfish/): Goldfish are the most popular aquarium fish. And they probably have more controversy than any other fish. This is because of a very concerted campaign by PETA ("People for the Ethical Treatment of Animals") to prevent the keeping of ANY fish in an aquarium, with goldfish being their first target. The whole thing can be - [17.4. Lake Malawi Cichlids](https://aquariumscience.org/17-4-lake-malawi-cichlids/): Probably most fish keepers gravitate over time to aquariums of Lake Malawi Cichlids. This is due to the incredible colors which rival those of reef dwelling fish. So this article discusses largely Lake Malawi cichlids. Note that most of the photos in this article will drive the fish police absolutely bonkers. They have Lake Malawi, - [17.3. Blackwater Fish](https://aquariumscience.org/17-3-blackwater-fish/): Summary of Blackwater Fish Needs The term "blackwater" refers to soft, acidic water which is deep brown in color, like clear tea. The dark brown color is due to organic acids in the water. Many river systems of northern South America including the Rio Negro and the Orinoco have blackwater. Some streams and swamps in - [17.2. Biotopes](https://aquariumscience.org/17-2-biotopes/): Many ascribe to the concept of “biotopes”, where fish and plants from a certain region are grouped together. These biotopes are: Central American Central American Lake Central American Stream South American South American Blackwater South American Clearwater South American Whitewater African Rift Lake Region Lake Malawi Rock Dwellers (mbuna) Free Swimmers (“Haps”) Sand Sifters (Peacocks) - [17.1. Native Water Chemistries](https://aquariumscience.org/17-1-native-water-chemistries/): A valid question is what fishes are found in each category of water chemistry. One shouldn't worry much about keeping a perfect pH or hardness (KH and GH) in aquariums. Most fish can adapt to anything from a 6.5 to an 8.5 pH and any KH and GH. I've mixed fish from radically different native - [17. Aquarium Fish Selection](https://aquariumscience.org/17-aquarium-fish-selection/): Myths About Selecting Fish for the Aquarium Selecting fish has become very controversial with the advent of social media and the many people who parrot a myth over and over again. These purveyors of myths about fish selection are known with some disdain as the "fish police". Some of the myths about fish selection include: - [16.2. Controlling Algae](https://aquariumscience.org/16-2-controlling-algae/): Algae control is difficult because there thousands of algae species, including something called "blue green algae" (cyanobacteria) which isn't even an algae. So making blanket statements is somewhat misleading. Each algae (or bacteria) species responds differently to different courses of action. This variability across species is the result of a very natural process called "niche - [16.11. Slime Mold](https://aquariumscience.org/16-11-slime-mold/): One very interesting organism found occasionally in aquariums is called a “slime mold” (Myxogastria). This is somewhat like a cross between an amoeba and a fungus. It can very slowly move overnight, forming new networks and structures with hyphae like a fungus. It can also separate into thousands of single cells which move away from - [16.8. Brown Algae](https://aquariumscience.org/16-8-brown-algae/): "Brown Algae" in a Nutshell “Brown algae” or “diatoms” occurs in all aquariums. The terms "algae" and "diatoms" are misnomers in that there are many different organisms which can predominate in a brown film on an aquarium surface. If one just leaves "brown algae" alone it will lessen in four to six months. Bushy nosed - [16.7. Aquarium Green Water](https://aquariumscience.org/16-7-aquarium-green-water/): Green Water is algae suspended in the water column of the aquarium. Typically a microscopic analysis will reveal many different types of algae in green water. There are almost always also a lot of "infusoria" in the water, minute microscopic critters and bacteria. So this literally is a soup of many different organisms. Most green - [16.6. Staghorn Algae](https://aquariumscience.org/16-6-staghorn-algae/): Staghorn algae is a type of red algae that forms coarse long strands of gray green to solid green color. Sometimes it is almost white colored. It is very unsightly. It grows on the edges of plant leaves as well as on the edges of almost any hard surface. Composed of coarse strands or tufts, - [16.5. Black Beard Algae](https://aquariumscience.org/16-5-black-beard-algae/): Black beard algae (also called BBA and brush algae) is botanically a red algae. If you put red algae in alcohol, they will turn reddish. This is an easy proof that the algae you're dealing with are actually red algae. Black beard algae grows on the edges of plant leaves as well as on the edges - [16.4. Blue-Green Algae](https://aquariumscience.org/16-4-blue-green-algae/): What is "Blue Green Algae"? "Blue Green Algae" is not an algae. It is a bacteria form called a cyanobacteria. The name cyanobacterium is derived from the Greek word for “blue”: κυανός. Cyanobacteria is normally blue-green in color, as the name suggests. But cyanobacteria can also be yellow green, reddish brown or even purple. And - [16.3. Thread Algae](https://aquariumscience.org/16-3-thread-algae/): Thread algae, hair algae or green hair algae is most often (but not always!) a filamentous green algae (Chlorophyta). Thread algae are a quite commonly found green algae. They form carpet-like layers, growing over plants and decoration. There are many types and forms of filamentous green algae. Very fine pale green brown strands are typically - [16.9. Green Spot Algae](https://aquariumscience.org/16-9-green-spot-algae/): Green spot algae, also known as green coat algae, is found in every aquarium. These green algae (chlorophyta), which cover glass and structures, are relatively easy to clean because we have the most weapons to combat them, including: algae scrubbers, and algae-eating catfish and invertebrates. As green algae, they do not cling tenaciously to surfaces - [16.1. Algae Biology](https://aquariumscience.org/16-1-algae-biology/): I deliberately added a "gotcha" photo, above, at the top of this article. Most hobbyists would say this tank has an obvious "algae" problem. It doesn't. The green mat on the substrate is probably not an algae, it is probably a bacteria. And the gray wispy "stuff" is probably something called a "water mold" which - [16. Aquarium Algae](https://aquariumscience.org/16-aquarium-algae/): Algae are a problem for most fish keepers. The problem is that most “newbies” try to fight the algae and eliminate it from their aquarium. This is simply impossible. The best way to fight algae is to keep nitrates low in the aquarium with water changes. This also keeps phosphorus low in the aquarium. This - [15.6. Carbon Dioxide](https://aquariumscience.org/15-6-carbon-dioxide/): Unless one has some very easy aquarium plants (anubias, Amazon sword, Java fern, Java moss) a planted aquarium needs a source of carbon dioxide. Carbon dioxide (CO2) does help a great deal with any planted tank. The Aquapros YouTube channel (great channel!) ran a test of CO2 injection. For 40 days they ran two aquariums - [15.5. Aquarium Fertilizing](https://aquariumscience.org/15-5-aquarium-fertilizing/): There are several methods of fertilizing a planted aquarium: The easiest approach to planted aquarium fertilizing is to simply use a "ready-made" fertilizer like Aquarium Co-Op Easy Green™ per the instructions on the container. Easy. Simple. Effective. But this method is not cheap. Adding an expensive complete commercial liquid fertilizer "program" to the water column - [15.1. Planted Aquariums in Depth](https://aquariumscience.org/15-1-planted-aquariums-in-depth/): There are as many good ways to set up a planted aquarium as there are good ways to set up a fish only aquarium. But surprisingly plants are more difficult than fish are. Growing lush plants can be tricky. Growing lush plants without growing lush algae can also be challenging. And adding large numbers of - [15.3. Fish Limitations](https://aquariumscience.org/15-3-fish-limitations/): I’ve seen thousands of aquariums with lots of fish in them and hundreds of aquariums with lots of plants in them. Notable almost absent from the vast majority of these thousands of tanks are tanks which have both large amounts of plants and moderate amounts of medium sized or large fish. It is just VERY - [15.2. Fish](https://aquariumscience.org/15-2-fish/): Cardinals, rummy nose tetras and harlequin rasboras seem to be the fish of choice almost as an after thought in many planted aquariums. There are some good alternatives. Planted aquariums can be stunning with schools of various “nano fish”. A good option is schools of six or more Ember Tetra, various small danios, Celestichthys margaritatus - [15.4. Types of Planted Tanks](https://aquariumscience.org/15-4-types-of-planted-tanks/): Many of the successful planted aquariums in the world are very simple affairs without carbon dioxide additions and pretty much ANY combination of substrates, plants, aeration and filtration. And as long as they follow one "guideline" they can do well. This one "guideline" is: . Only have a Few Small Fish in the Planted Aquarium - [15. Planted Aquarium](https://aquariumscience.org/15-planted-aquarium/): Planted Aquariums in Depth We go into more guidelines for all aquariums more in this article: 15.1. Planted Aquariums in Depth The following sections will give you some general guidelines on the easiest ways to set up a beautiful planted aquarium: 15.2. Fish for Planted Tank 15.3. Fish Limitations 15.4. Types of Planted Aquariums 15.5. - [14.9. Wavemakers](https://aquariumscience.org/14-9-wavemakers/): Some terminology needs to be clarified when it comes to submersible pumps commonly used inside the aquarium: Powerhead: originally a centrifugal impeller pump used to drive an under-gravel filter that drew in water through the bottom of the pump (vertically) and then expelled it from the side of the pump horizontally in a forceful concentrated - [14.8. Aquarium Heaters](https://aquariumscience.org/14-8-aquarium-heaters/): Heaters are one of the most overlooked pieces of equipment in this hobby. They are the number one cause of tanks crashing and losing an entire tank of expensive prized fish. This is very unfortunate because they are actually one of the most affordable pieces of equipment and something we have the most control over. - [14.7. Overflow Devices](https://aquariumscience.org/14-7-overflow-devices/): When one uses a sump the pump in the sump moves the water back up to the aquarium. Then there needs to be a way of moving the water back to the sump and to prevent the aquarium from overflowing. There are a huge number of DIY devices on the internet and YouTube that are - [14.6. Pumps](https://aquariumscience.org/14-6-pumps/): Pumps are essential to an aquarium. There are many types of pumps available: The pumps built into most canisters are cheap external magnetic drive pumps that don’t work very well against any degree of back pressure or head. They work reasonably well in a canister because the water return from the aquarium to the pump - [14.5. Piping](https://aquariumscience.org/14-5-piping/): Over the years I’ve had many cases of failed plumbing. And I’ve learned to avoid any plumbing which doesn’t conform to the building code for potable water in the home. A leak can just be disastrous. Ribbed Tubing Recently Joey had a major leak on his 2,000 gallon tank when some large tubing tore open. - [14.4.2. Obsolete Standards](https://aquariumscience.org/14-4-2-obsolete-standards/): There were many light standards which were developed for the incandescent bulb. With the advent of the fluorescent tube and LEDs most of these standards become obsolete. But one sees them still used to refer to the lights' "strength" and spectral analysis. The standards include lumens, degrees Kelvin (°K) and PAR. A shop white LED - [14.4.1. Light Spectrums](https://aquariumscience.org/14-4-1-light-spectrums/): Before reading this post it is best to go to this link and read the over-all article on aquarium lighting: 14.4. Aquarium Lighting Aquarium lights are used to illuminate the aquarium fish. What few recognize is that the intensity of a fish’s color is determined to a strong degree by the lights over the aquarium. - [14.4. Lights](https://aquariumscience.org/14-4-lights/): Lighting is essential for the aquarium. It is an integral part of enjoying the aquarium. But lighting has become a very complex issue. The number of options has become huge. The old fluorescent tube aquarium fixtures have become a thing of the past. The new LED fixtures have taken over. Each of these fixtures has - [14.3. Rocks](https://aquariumscience.org/14-3-rocks/): Summary of Rock Data ALL rocks and stones you will find in your rock yard, yard, or the local stream are fine just as is (i.e. no boiling or bleach), including those that bubble with acids like vinegar. Shells and corals are also perfectly safe with no treatment as are almost all gemstones, semi-precious stones, - [14.2.4. Anaerobic Myth](https://aquariumscience.org/14-2-4-anaerobic-myth/): One of the biggest myths, repeated over and over by a host of well meaning but ill-informed commentators on social media, is that anaerobic or anoxic conditions can exist in an aquarium in the substrate if the substrate is deep enough. Per these individuals, conditions in some substrates (generally something called a "deep sand bed") - [14.2.3. Buffering Substrates](https://aquariumscience.org/14-2-3-buffering-substrates/): It is beneficial for most aquariums to add a bag of crushed coral to the filter. This buffers the water to 7.6 to 7.9 pH. This pH is great for all fish, contrary to popular mythology. Also beneficial is using crushed coral, oolitic limestone sand or aragonite sand as a substrate. These substrates see very - [14.2.4.1. Anaerobic Science](https://aquariumscience.org/14-2-4-1-anaerobic-science/): Synopsis This whole topic can be condensed into one statement: Anaerobic or Anoxic Conditions do not Occur in the Home Aquarium Except in the Intestines of Fish . This is an in depth analysis of two related myths: Anaerobic conditions in a substrate allow nitrates to be reduced to nitrogen gas Anaerobic conditions in a - [14.2.1. Sand](https://aquariumscience.org/14-2-1-sand/): Sand is probably the most common substrate. Sand doesn’t allow food particles to drop down uneaten into the substrate. And most people like the aesthetics of white sand in an aquarium. But it has its limitations. The fines it produces CAN destroy a pump impeller in weeks to months (depends a lot on the pump - [14.2. Substrates](https://aquariumscience.org/14-2-substrates/): There are many options when it comes to the substrate one uses in an aquarium. Substrate options condensed into a table are: My recommendation is “natural” aquarium gravel. The cream through brown varied color hides accumulated detritus and feces. Mono-colored substrate such as sand or black diamond simply look really bad when fish poop, which - [14.1.2 Selecting a UV Unit](https://aquariumscience.org/14-1-2-selecting-a-uv-unit/): Sizing UV Units Wide spread social media consensus (including profit driven internet directions and the directions that come with the units), is that UV in the home aquarium needs to have high wattages, low flows, high dwell times, splitters or flow control valves to be very effective. This is simply incorrect. High flow rates, low - [14.1.1. UV in Depth](https://aquariumscience.org/14-1-1-uv-in-depth/): Like most of the "In Depth" articles in this website this is very long and boring dissertation. Only read on if one needs to take a nap. Aquarium UV in Greater Depth "UV" is short for ultraviolet. It is a type of light. Per Wikipedia: “UV light is electromagnetic radiation with wavelengths shorter than visible - [14.1. UV Sterilizers](https://aquariumscience.org/14-1-uv-sterilizers/): UV sterilizers are small electrical light treatment units which have water flowing over a special electric light bulb. This special bulb puts out an invisible high energy type of light called UV light. UV light is what causes sunburns in humans exposed to the sun for too long. This UV light kills micro-organisms in the - [14. Equipment](https://aquariumscience.org/14-equipment/): This is a chapter dedicated to aquarium hardware. This includes the UV units, substrate, pumps, plumbing, heaters and decorations. Each product will have its own article. There are many myths about equipment, substrates and decorations parroted around social media. Some of these are: Since UV units don’t filter, they can’t give crystal-clear water. Aquarium UV - [13.3. Lifespan of a Fish](https://aquariumscience.org/13-3-lifespan-of-a-fish/): Before you rush out and buy 700 two-inch fish to populate your one-hundred-gallon aquarium be aware of one shortfall to small fish, they don’t live long. Most two-inch fish only live two to five years. Live bearers typically live shorter lives than egg layers. So, an aquarium full of guppies is tempting but they might - [13.2. Calculating Stocking Ratio](https://aquariumscience.org/13-2-calculating-stocking-ratio/): This is a very long and boring discussion of the very charged and opinionated topic of proper stocking of the aquarium. This article tackles the problem from a scientific viewpoint. This is very long winded discussion only for real nerds, like the author. The Science Note that there is some science here. And the science - [13. Stocking](https://aquariumscience.org/13-stocking/): If one is new to fishkeeping, stocking is best looked at not by numbers but rather by water clarity. Slowly add some fish. Then see how it goes. Keep looking down the length of the tank and judging how clear the water is. If the water looks even a little bit cloudy do not add - [5.5.3.6. Review of Conditioners](https://aquariumscience.org/5-5-3-6-review-of-conditioners/): My recommendation with conditioners is simple: . Buy ONLY Conditioners that say "Sodium Thiosulfate" on the Bottle in the Ingredients List. Then use 5X the Recommended Dosage. . When I used to have chlorinated water for a 60 gallon tank 50% water change I would take the amount of thiosulfate conditioner which would, per the - [5.5.3. Water Conditioners](https://aquariumscience.org/5-5-3-water-conditioners/): Most water supplies in the developed world have either chlorine or chloramine in them to kill bacteria and prevent disease outbreaks. This chlorine and chloramine need to be neutralized before it gets to the gills of a fish as it is very toxic to the fish. This is done with something called a "conditioner". All - [12.6. Sterilization](https://aquariumscience.org/12-6-sterilization/): When an aquarium has had a virulent organism such as the bacteria columnaris wipe out most of the aquarium many people try to sterilize the aquarium and its contents. Some people use disinfectants such as ¼ cup of bleach in a gallon of water to wipe down and “disinfect” an aquarium which has had an - [12.5. Fish Don’t Drink](https://aquariumscience.org/12-5-fish-dont-drink/): This article only proves one should put medication into the food and not into the water, if one is treating an internal disease of a fish. If you believe that statement just stop right here. If one questions that statement, read on. But note the "proof" below is lengthy and only meant for real nerds - [12.4.7. Quinine](https://aquariumscience.org/12-4-7-quinine/): One very typical example of the profit motive at work is the promotion of Chloroquine Phosphate as an ich medication. The claims put out by the manufacturer of the product, as usual, combine fact with fiction in a blend that deceives many people. The manufacturer claims Chloroquine Phosphate kills the malaria organism, a true statement. - [12.4.6. Furan and Sulfa](https://aquariumscience.org/12-4-6-furan-and-sulfa/): Sulfa and Furan Drugs Sulfa and furan drugs do not treat fish diseases very well. They should be thought of as antiseptics which have limited bacteriostatic actions when dissolved in the water column of an aquarium. They will stop the transmission of bacteria from one fish to another fish. They are far more effective when - [12.4.5. Antiseptics](https://aquariumscience.org/12-4-5-antiseptics/): There are many medicines marketed for fish diseases which are properly termed antiseptics (other terms are disinfectants and anti-bacterials). These are frequently touted for use in fish for treating fish diseases. The following antiseptics are commonly touted for treating fish pathogens: Glutaraldehyde (Paraguard) Hydrogen peroxide Peracetic acid (MinnFinn) Potassium permanganate (UltraClear) Potassium peroxymonosulphate (Virumor) N-halamine - [12.4.4. Formalin](https://aquariumscience.org/12-4-4-formalin/): Some medications use a compound called formalin in them. Formalin is simply a 30% solution of formaldehyde, the stuff which preserves frogs for dissection. Believe it or not, this compound supposedly kills all the following pathogens; ich costia chilodonella trichodina fungus flukes protozoan parasites algae fungi crustaceans In actuality this is true. At a high - [12.4.3. Aquarium Dyes](https://aquariumscience.org/12-4-3-aquarium-dyes/): Malachite green and methylene blue are very old remedies which were put forth in the 30’s and 40’s as fish medications. They are aniline dyes. They have a well documented ability to selectively control ich, the most common tropical fish disease. They are also very mild antiseptics which are useful for killing saprolegnia ("fungus") and - [12.4.2. Salt](https://aquariumscience.org/12-4-2-salt/): Summary of Salt Treatments for Fish Salt is often recommended as a “natural” medicine for fish. There are many levels of salt that can be used with fish: 0.1 to 1.2 parts per thousand or half a teaspoon to four tablespoons of salt per 10 gallons to an aquarium is a “general tonic very beneficial - [12.4.1. “Natural” Aquarium Medications](https://aquariumscience.org/12-4-1-natural-aquarium-medications/): There are a whole host of aquarium medications which are labeled as "Natural". Sorry, I just cannot sugar coat this: . "Natural" Medications are ALL Worthless . ALL the claims made for "natural medications" on social media are simply parroted marketing hype designed to make money. I.e. they are all simply "snake oil" and will - [12.4. Ineffective Medicines](https://aquariumscience.org/12-4-ineffective-medicines/): All the medicines mentioned in this article can be obtained in large quantities for reasonable prices. Yet none of them are used in commercial aquaculture of fish to treat any diseases (formalin is a notable exception). That is because they are either dangerous or they don’t work. The profit motive will always tell you a - [12.3. Quarantine Tanks](https://aquariumscience.org/12-3-quarantine-tanks/): Quarantine aquariums are essential for the serious hobbyist. They are the best way to prevent serious fish diseases. Newly purchased fish are kept in the quarantine tank for four to eight weeks to see if disease pops to the surface. . Always keep a new fish in a quarantine tank for at least four weeks. - [12.2. Treatments Summary](https://aquariumscience.org/12-2-treatments-summary/): Summarizing, the medications which can be used for freshwater aquarium fish are: There is one very important point here. These medications are generally the only disease treatments which are supported by science. There are a few exceptions in that there are a some five alternatives to the formalin/malachite green treatment. But there are not options - [12.1. Basics of Treatment](https://aquariumscience.org/12-1-basics-of-treatment/): This article goes over some of the basics for medications: Stock of medications Medications and scaleless fish Medications and beneficial bacteria Stock of Drugs It is very important to be prepared. Fish disease can move fast, very fast! A typical stock is: MetroPlex (metronidazole or “metro’” for "stringy white poop” [“Hexamita”] and “internal parasites”) Fenbendazole - [12. Treatment](https://aquariumscience.org/12-treatment/): Diseases are generally not a problem in aquariums which have over-filtered, crystal clear, bacteria free water. . The Key to Good Fish Health is Clean, Bacteria Free Water . Note this does not mean water which is changed frequently. The idea that water changes create good health is a myth. The idea that water which - [11.15. Fish not Eating](https://aquariumscience.org/11-15-fish-not-eating/): If fish are not eating well or just acting different most hobbyists pick up on it quite rapidly. There are several reasons for "not eating". Cichlids such as Oscars are prone to stop eating seemingly just for spite. They can go for weeks without eating, then start eating again with gusto, apparently perfectly healthy. They - [11.14. Scaly Skin](https://aquariumscience.org/11-14-scaly-skin/): Fish are often described as having scaly burnt skin. This condition is generally due to the local water municipality doing a "chlorine pulse". Since the chlorine has also hit the gills, the fish need to be treated by heavy aeration. Dropping the temperature also helps. This condition is rare. At the chlorine concentrations that do - [11.13. Slime Coat](https://aquariumscience.org/11-13-slime-coat/): Slime coat syndrome is when the mucus on a fish is produced in such amounts that it sloughs off the fish and gives a ragged appearance to the fish. The fish will have subdued colors due to the thick mucus. This is called “slime coat syndrome” (excess mucus on the body). If you analyze the - [11.11. Red Skin Blotches](https://aquariumscience.org/11-11-red-skin-blotches/): When a fish gets red skin blotches invariably everyone on social media will immediately comment that the fish has ammonia poisoning. They are generally wrong. There are two distinct types of red blotches seen on fish: Blood red blotches. These are hemorrhagic septicemia caused by bacteria. These are what are seen in the home aquarium. - [11.10. White Skin Blotches](https://aquariumscience.org/11-10-white-skin-blotches/): An often-heard complaint in aquarium social media is “My fish have white blotches on their skin”. This can be a lot of things. There is the obvious well known “white spots” caused by ich. Then there are a host of diseases often confused with one another. These include the following: . Identifying which “white blotch” - [11.9. Spinal Deformities](https://aquariumscience.org/11-9-spinal-deformities/): Spinal deformities come in three variations: Congenital spinal deformities are present at birth or shortly there after. A slow bowing of the spine over time is typically fish TB A rapid bowing of the spine over a few days is typically columnaris bacterial infections. Congenital Spinal Deformities Deformites which are present at birth typically are - [11.8. Twirling](https://aquariumscience.org/11-8-twirling/): A common fish symptom is “spinning”, “twirling” or “whirling”. Many hobbyists mistake this with swim bladder disease. But in swim bladder the fish assume an abnormal posture. In “twirling”, there is no posture at all. This symptom is most often caused by a gram-positive bacterium. Per the book “Fundamentals of Ornamental Fish Health”, Helen Roberts, - [11.7. Shimmying](https://aquariumscience.org/11-7-shimmying/): Fish suffering from the shimmies rapidly quiver as they swim, rocking from side to side. Shimmying is a symptom rather than a single disease, and an indication that a fish no longer has proper control of its nerves and muscles. All of the following can cause shimmies: Genetics (especially the molly) An internal bacterial infection - [11.6. Swim Bladder](https://aquariumscience.org/11-6-swim-bladder/): Swim bladder syndrome is can be seen occasionally in the aquarium. The swim bladder is an internal gas-filled organ that allows the fish to control its buoyancy, and thus to stay at the desired water depth without having to waste energy in swimming. A fish with swim bladder disorder will sink to the bottom or - [11.5. Hollow Belly](https://aquariumscience.org/11-5-hollow-belly/): If most of the fish in an aquarium have “hollow belly” this is generally due to lack of enough food. If only a few fish have a “hollow belly” the number of possible pathogens is in the hundreds. Causes of "Hollow Belly": Fish get “hollow belly” because some pathogen is interfering in the normal absorption - [11.4. Dropsy](https://aquariumscience.org/11-4-dropsy/): Dropsy and bloat are two conditions seen often in fish. Both mean a fish which is swollen up. The terms are sometimes used interchangeably and sometimes they have different meanings. This article will use the following differential: It is important to differentiate between dropsy and bloat. If the fish has bloat go to this link: - [11.2. White Poop](https://aquariumscience.org/11-2-white-poop/): In “stringy white poop” the feces will stick to the fish and trail behind it in thin clear or white threads with brown patches. Stringy clear or white poop CAN be mucus from severely infected intestines. Most of the time it means nothing. White poop or clear poop in fish is like diarrhea in humans. - [11.1.2. Spots on Head](https://aquariumscience.org/11-1-2-spots-on-head/): A very common disease of small cichlids and sometimes other types of fish is the appearance of small white spots, like fluffy pimples, on both sides of the fish’s head. This is called "canal neuromast inflammation" or "CNI". This also manifests as a big "scrape" on the forehead, like an open sore on the forehead - [11.1.1. Hexamita and HITH](https://aquariumscience.org/11-1-1-hexamita-and-hith/): Many people (and many “expert's” advice web pages) consider "hexamita" (technically the organism is spironucleus, not hexamita) as not only the primary cause of hole-in-the-head syndrome but also the name of the disease. This is simply incorrect. Water quality issues, NOT "internal parasites", are by far the chief cause of hole in the head syndrome. - [11.1. Hole in the Head](https://aquariumscience.org/11-1-hole-in-the-head/): Hole-in-the-head (HITH or Head and Lateral Line Erosion [HLLE]) syndrome is just that. It appears as holes and open pitted wounds around a fish's head and along the lateral line, as if something is slowly eroding away the flesh. Many call this a disease but since it is caused by a great many environmental conditions - [11. Fish Disease Symptoms](https://aquariumscience.org/11-fish-disease-symptoms/): One caution about diagnosing fish diseases. Even with a microscopic examination fish diseases are not easy to diagnose. Most hobbyists have only what their eyes tell them to go on as to what any fish disease is. This means that diagnosis of any fish disease is simply a "best guess". And these "best guesses" are - [7.4.8. Chemi-pure](https://aquariumscience.org/7-4-8-chemi-pure/): There are several varieties of a “Proprietary Product” called Chemi-pure. These are simply mixtures of the products below with very high price tags. Activated carbon will do the following: It will remove smells from a poorly aerated aquarium It will remove food coloring from cheap fish food which colors the aquarium water yellow or green - [10.13.3. Planaria](https://aquariumscience.org/10-13-3-planaria/): Planaria are a type of flatworm or Platyhelminth. Other flatworms are flukes and tapeworms. Flatworms are very primitive organisms. All flatworms have relatively wide very flat bodies. They look like earthworms which have been flattened by a rolling pin. They just kind-of magically glide on a film of mucous. They do not swim free in - [10.13.2. Detritus Worms](https://aquariumscience.org/10-13-2-detritus-worms/): "Detritus worms" are found in virtually all aquariums. They are typically small long white worms which wiggle about in the substrate. They are very beneficial to the aquarium and should just be left alone. Too many detritus worms indicates one is over feeding. Read on if you are interested in being bored. Detritus Worms in - [10.13.1. Hydra](https://aquariumscience.org/10-13-1-hydra/): Hydra are small creatures often found attached to the aquarium glass, rocks and decorations in the aquarium. Hydra are small-sized polyps from the same phylum (Cnidaria) as sea anemones, corals and jellyfish and resemble tiny anemones. While anemones are marine, hydra lives only in freshwater. Hydra have a tubular body attached to a surface at - [10.13. Pests](https://aquariumscience.org/10-13-pests/): Sometimes small critters come into an aquarium on plants or fish and become established. The most common denizens aquarium owners find are hydra, detritus worms, planaria and leeches. These are pictures of four of these pests: . People often talk about “worms” in an aquarium and recommend “dewormers” to deal with them. This is somewhat - [10.9. Anchor Worms](https://aquariumscience.org/10-9-anchor-worms/): Anchor worms are a parasite of tropical fish which have visible parts which look like white cotton threads 1/8 to 1 inch long hanging off the body or fins of a fish. The short white threads move with the current, which distinguishes them from any other disease such as ich. It was once thought there - [10.11. Tapeworms](https://aquariumscience.org/10-11-tapeworms/): There is a close relative of flukes known as tapeworms. Tapeworms live in the digestive tract of a fish as adults. The larval stage of some species of tapeworms live inside the body cavity of the fish. In other fish tapeworms, snails and even birds can harbor the larvae stages. Per Norbury 2022; "Cestodes, known - [10.10. Black Spots](https://aquariumscience.org/10-10-black-spots/): There are many species of "black spot" flukes. They are poorly studied. Almost all species have a life cycle which goes through birds, then snails, then fish, then birds etc. As a result, black spot is almost always found in fish which have been raised in ponds. They all seem to be pretty harmless and - [10.6. Flukes](https://aquariumscience.org/10-6-flukes/): Another external parasite of fish is monogenean flukes; microscopically small, flat oval segmented flatworms (Platyhelminths). They are small relatives of the planaria. There are two types of flukes commonly seen on fish: Gyrodactylus (skin fluke) and Dactylogyrus (gill fluke). Flukes typically can’t be seen on the fish. Symptoms Skin flukes produce twitching and flashing as - [10.8. Lymphocystis](https://aquariumscience.org/10-8-lymphocystis/): Fish commonly get a white to pink cauliflower like growth on their bodies. The disease is often referred to as “Cauliflower Disease”. It’s called Lymphocystis. Makes a wart on the fish. It is caused by a virus belonging to the Iridoviridae family. Generally, the growths are white to pink but sometimes the growth takes on - [10.7. Fish Saprolegnia](https://aquariumscience.org/10-7-fish-saprolegnia/): "Fungus" or Saprolegnia Summary "Fungus" on a fish is typically a ball of white filaments sticking out well beyond the skin of the fish. The term "fungus" is a misnomer as these are not truly a "fungus", they are saprolegnia water mold, a distant relative of the diatom. Most saprolegnia infections are either secondary to - [10.12. Nematodes](https://aquariumscience.org/10-12-nematodes/): There are two types of nematodes or roundworms which are common pathogens on aquarium fish: capillaria and camallanus. These two worms are covered in separate sections with links below. Well-maintained fish may be infected without exhibiting any symptoms at all, and nematodes worms are commonly found among wild fish without any obvious link between infection - [10.5. Hexamita](https://aquariumscience.org/10-5-hexamita/): Hexamita is the common terminology used to describe many Hexamitidae Spironucleus species. Some use the term "internal parasites" to describe hexamita. There are hundreds of "internal parasites" of fish so we won't use that terminology. Hexamita is responsible for some portion of a whole series of symptoms including “white poop”, bloat, hollow belly, wasting disease, - [10.4.1. Fish TB in Depth](https://aquariumscience.org/10-4-1-fish-tb-in-depth/): This article is a very in depth look at "Fish TB". It is only of interest to the real nerds, like the author. If one wants to be bored to tears read on. What is "Environmental Mycobacteriosis" The word “Environmental” in Environmental Mycobacteriosis (EM or Fish TB) is important. Environmental means an organism commonly found - [10.4. Fish Tuberculosis](https://aquariumscience.org/10-4-fish-tuberculosis/): Fish tuberculosis or fish TB (also more properly called Environmental Mycobacteriosis or EM) is a bacterial disease which is different. There is no effective medication available to the hobbyist for fish TB. This sets it apart from the other bacterial diseases. It is also unusual in that it is the only fish disease which humans - [10.3.11. Treating Bacteria](https://aquariumscience.org/10-3-11-treating-bacteria/): If one has more than one fish with a bacterial disease, one must treat the whole aquarium. This is an emergency. Don’t fool around with herbs or some ineffective treatment. Ben Ochart treated a bacterial infection with Pimafix and Melafix. They did nothing to stop the infection. He lost a lot of large beautiful fish - [10.3.1. Skin Ulcers](https://aquariumscience.org/10-3-1-skin-ulcers/): Saddleback and white spot can become pink or red open lesions or ulcers. Ulcers caused by bacteria come on quickly and are typically flat. This contrasts to the ulcers caused by fish TB which come on slowly and are raised bumps that slowly break open into raised edged ulcers. Ulcers in fish are most often - [10.3.9. Red Gills](https://aquariumscience.org/10-3-9-red-gills/): Gram negative columnaris bacteria can invade the gills and cause “gill disease”. The gills become red or brown and inflamed, there can be spots of red at the base of the pectoral fins and a thin papery look is found on the gill plate due to mucus. The fish hangs in the water and “pants” - [10.3.8. Popeye](https://aquariumscience.org/10-3-8-popeye/): In “Popeye” the fish’s eyes bulge out. Popeye can be caused by many things, injury to the eye, environmental mycobacteriosis, even viruses. But the most common cause is a bacterium called Corynebacterium. This is a gram-positive bacterium best treated with erythromycin (API E.M. Erythromycin, Mardel Maracyn, Thomas Labs Fish Mycin) or penicillin. Bacterial infections are - [10.3.7. White Eyes](https://aquariumscience.org/10-3-7-white-eyes/): If only one eye is white it is typically a minor bacterial eye infection caused by the fish scrapping its eye or from an attack by another fish. If both eyes are white it is coming from a more serious bacterial infection inside the fish and will kill the fish rapidly. This is most often - [10.3.6. Red Blotches](https://aquariumscience.org/10-3-6-red-blotches/): Most blood red blotches on the fins or skin of tropical fish are blood under the skin or hemorrhagic septicemia (“Red Pest”), an internal bacterial disease. The bacteria is generally a gram negative bacteria, with aeromonas bacteria being the chief culprit. Hemorrhagic septicemia is a very serious conditions from which fish have very high mortalities, - [10.3.5. Saddleback](https://aquariumscience.org/10-3-5-saddleback/): Flat, fuzzy, velvety white patches on the body of a fish are often seen. This is typically in a “saddle” shape on the back, thus the term “saddleback”. This is most often gram-negative bacteria (columnaris, aeromonas, etc.). This is often called "fungus" by newcomers to the hobby. A fuzzy patch which only stick out slightly - [10.3.4. Fin Rot](https://aquariumscience.org/10-3-4-fin-rot/): Fin rot is when the fins of a fish start eroding. Typically the eroding fins will have white edges. If white edges aren’t present it could be fin nipping and aggression which has caused the problem. This is most often gram-negative bacteria (columnaris, aeromonas, etc.). Treatment Fin rot should be treated with broad spectrum antibiotics - [10.3.3. Duck Lips](https://aquariumscience.org/10-3-3-duck-lips/): “Duck lips” are simply fat lips. There are two types of 'Duck Lips" in aquarium fish. One is caused by bacteria and is normally a rapid killer. And one form, which only occurs in Lake Malawi cichlids, is a virus which comes on slowly and can be very benign. The bacterial form is typically caused - [10.3.2. Mouth Rot](https://aquariumscience.org/10-3-2-mouth-rot/): Mouth rot is a patch of white stuff on a fish’s lips. As the disease advances it produces toxins that erode the lips of the fish. Advanced cases get very ugly and the fish can’t eat. Names for this disease include cotton-mouth, mouth fungus, and flexibacter. This is most often gram-negative bacteria (columnaris, aeromonas, etc.). - [10.3. Bacterial](https://aquariumscience.org/10-3-bacterial/): There are many ways and many bacterial species which attack tropical fish in the aquarium. These diseases move much faster that other pathogens and can kill fish rapidly. It is very important to keep a stock of good antibiotics in the refrigerator to treat fish without delay. A two day wait for Amazon to get - [11.16. Aggression](https://aquariumscience.org/11-16-aggression/): Aggression is a very common issue in fish aquariums, especially cichlid aquariums. Lake Malawi cichlids are very aggressive and some Central American cichlids are almost as bad. Aggressive fish ram the less dominant fish, creating areas where the scales fall off. Fins get tattered and secondary bacterial infections set in. Fish which are the victims - [10.2.7. Cryptobia](https://aquariumscience.org/10-2-7-cryptobia/): There is a ciliated protozoan that attacks cichlid fish internally. It is called Cryptobia. There are many species of cryptobia with considerable differences in how they present themselves. The organism is a small flagellated organism very similar in appearance to Hexamatadea spironucleus (hexamita, the cause of most bloat and dropsy). Cryptobia was first recognized as - [10.2.5. Chilodonella and Costia](https://aquariumscience.org/10-2-5-chilodonella-and-costia/): A patchy greyish-white “beat up” look on the body with some spider-webbing and a roughened appearance is indicative of an infestation by a microscopic external protozoan parasite such as Chilodonella or Costia (Ichthyobodo). This is oftentimes difficult to differentiate from bullying. The patchiness is typically rather diffuse as opposed to the more well-defined white spots - [10.2.4. Epistylis](https://aquariumscience.org/10-2-4-epistylis/): Epistylis is a disease commonly confused with ich. It can look almost identical to ich. Epistylis is typically fuzzy and translucent while ich is clearly defined and very white. Epistylis stick out from the fish while ich only slightly protrudes from the fish. Epistylis is commonly found secondary to a bacterial infection. I recommend treating - [10.2.3. Velvet](https://aquariumscience.org/10-2-3-velvet/): “Velvet” (Piscinoodinium pillulare, or "oodinium", a dinoflagellate algae) is a very small parasite that looks like tiny spots of yellowish to golden-brown or rusty-colored varnish on the fish. Well intentioned but ill-informed commentators on the social media are constantly identifying patches of white on fish as "velvet". They are simply wrong. "Velvet" has a distinctive - [10.2.2.6. Filtration of Ich](https://aquariumscience.org/10-2-2-6-filtration-of-ich/): A curious pattern was noted by the author with regards to ich. The author did a survey of fish hobbyists. Some 70 hobbyists related that they had never had a fish die from ich. Only three reported they had fish die (all appeared to be "newbies" setting up new aquariums with new filters and doing - [10.2.2.5. Ineffective Ich Medications](https://aquariumscience.org/10-2-2-5-ineffective-ich-medications/): Ich simply is not normally fatal in ANY aquarium with an established filter because the established filter stops the ich organism. An established filter has a whole host of tiny, microscopic organisms on the surface of the filter media which can trap and literally eat the infectious ich theront. The longer a filter has been - [10.2.2.4. Ich Medications in More Depth](https://aquariumscience.org/10-2-2-4-ich-medications-in-more-depth/): MYTHBUSTER: ALL the well-done scientific studies by researchers on heat and ich have found heat to be totally ineffective in treating ich! Note there are two other diseases that look like ich (tetrahymena in livebearers and epistylis in other fish). So make sure you have ich. Public Aquariums use formalin/malachite green (Ich-X, Rid-Ich Plus, Blue - [10.2.2.3. Ich Medication](https://aquariumscience.org/10-2-2-3-ich-medication/): MYTHBUSTER: ALL the well-done scientific studies by researchers on heat and ich have found heat to be totally ineffective in treating ich! Note there are two other diseases that look like ich (tetrahymena in livebearers and epistylis in other fish). So make sure you have ich. Public Aquariums use formalin/malachite green (Ich-X, Rid-Ich Plus, Blue - [10.2.2.2. Ich Immunity](https://aquariumscience.org/10-2-2-2-ich-immunity/): Recent research has confirmed that the immune system of fish develops a resistance to the ich organism (University of Georgia, “Immunity to Ichthyophthirius Infections in Fish: A Synopsis”, Dickerson, et. al. 2014 and “Immune Response of Fishes to Ciliates”, Dickerson, et. al. 1996, and Tropical Fish Magazine, February 2014, “Preventing Ich” De-Hai Xu, PhD). Scientists - [10.2.2.1. Ich in Depth](https://aquariumscience.org/10-2-2-1-ich-in-depth/): MYTHBUSTER: ALL the well-done scientific studies by researchers on heat and ich have found heat to be totally ineffective in treating ich! Note there are two other diseases that look like ich (tetrahymena in livebearers and epistylis in other fish). So make sure you have ich. Public Aquariums use formalin/malachite green (Ich-X, Rid-Ich Plus, Blue - [10.2.2. Ich](https://aquariumscience.org/10-2-2-ich/): As in most of the articles on this website, the subject of ich will be discussed in layers. The simplest explanation is first, followed by a series of more complicated explanations. Then we have another series of links to articles on the topic of ich in even greater depth. Summary on Ich MYTHBUSTER: ALL the - [10.2.1. All Protozoans](https://aquariumscience.org/10-2-1-all-protozoans/): Many aquarium diseases are caused by external protozoan (single celled) parasites. External protozoan parasites of freshwater fish include ich, velvet, chilodonella, costia and epistylis. Most of these organisms follow a very similar course with the fish. They first infect the gills of the fish in large numbers. This is where a fish breathes. So, the - [10.2. Skin Protozoans](https://aquariumscience.org/10-2-skin-protozoans/): Skin protozoans, namely ich, are without a question the most common disease in fish. Treating ich and most skin protozoan diseases is actually very easy. Public Aquariums use formalin/malachite green (Ich-X, Rid-Ich Plus, Blue Planet White Spot Remedy and Mardel QuickCure) to treat ich in freshwater fish, as do University Research Centers, Cory of Aquarium - [10.1. Diseases in General](https://aquariumscience.org/10-1-diseases-in-general/): Fish die. If you have heavily stocked tanks fish die all the time. And easily 50% of the time even the best facilities like Cornell or the University of Florida can examine the fish and cannot tell you what the fish died from. Most fish diseases are subtle. And most diagnoses of fish diseases are - [10. Diseases](https://aquariumscience.org/10-diseases/): Diseases are generally not a problem in aquariums which have over-filtered, crystal clear, bacteria-free water. . The Key to Good Fish Health is Clean, Clear, Bacteria Free Water . Note this does not mean water which is changed frequently. The idea that water changes create good health is a myth. The idea that water which - [9.5. Aeration and Temperature](https://aquariumscience.org/9-5-aeration-and-temperature/): Many people tie aeration and temperature together by pointing out that the warmer the water the less oxygen it contains. This is true but is not that significant. 86-degree water contains 10% less oxygen than 75-degree water. So why do fish “pant” at the surface when the temperature is raised? This has to do with - [9.4. Skimmers and Spray Bars](https://aquariumscience.org/9-4-skimmers-and-spray-bars/): Skimmers Using a skimmer to “remove the floating proteins” is not recommended in freshwater aquariums. The water movement at the surface needs to be slow for these to work. “Slow” water movement at the surface means poor aeration, which is very unhealthy for the fish. There is also no such thing as “floating protein” in - [9.3.2. Cleaning Air Stones](https://aquariumscience.org/9-3-2-cleaning-air-stones/): Air stones last about six months before they become clogged. Some people use small cheap air stones that can be bought for fifty cents on Amazon. Recycling these is ridiculous. But some people like the expensive air stones ($5 to $20). It can pay to save these till some reasonable quantity are accumulated. Then clean - [9.3. Air Stones](https://aquariumscience.org/9-3-air-stones/): Bubble aeration is easy. Throw an air stone in an aquarium and you’ve got an aerator. But some, including myself, don’t like air stones. Both the bubbles themselves are noisy and the air pumps can be very noisy. And the wall or column of bubbles is obtrusive and unnatural in the aquarium. Many well meaning - [9.2. Turbulence and Aeration](https://aquariumscience.org/9-2-turbulence-and-aeration/): Good aeration in an aquarium is not a result of good water surface "movement". It is the result of "surface turbulence" or "bubble turbulence". The term "turbulence" refers to chaotic rapid movement of water in several directions at once, like the water movement in a rapids. Other ways of describing "surface turbulence" are "breaking the - [9.1. Aeration in Depth](https://aquariumscience.org/9-1-aeration-in-depth/): Aeration is creating a water/air interface in the aquarium where oxygen and carbon dioxide exchange can take place. Fish breath water. They need to get their oxygen from air dissolved into the water. So, this exchange is important. For good aeration one needs to have chaotic turbulent flow of water at the interface with the - [9. Aeration](https://aquariumscience.org/9-aeration/): One of the five keys to any healthy aquarium is aeration. In an aquarium with even moderate amounts of fish, aeration is essential for healthy fish. The aeration not only keeps the fish healthy, it keeps the beneficial bacterial populations healthy. One way to get good aeration is by having the surface of the aquarium - [8.9.2. A Feasible Reactor](https://aquariumscience.org/8-9-2-a-feasible-reactor/): Note Note that we have never set up a denitrifying reactor for our aquariums and will never set up such a reactor. We decidedly do NOT recommend that one build such a reactor to reduce water changes. It’s much easier to either do water changes or add plants to a set up. And denitrifying reactors - [8.9.1. Biocenosis Reactor](https://aquariumscience.org/8-9-1-biocenosis-reactor/): "Biocenosis reactors", "biocenosis clarification baskets", "BCBs", and "anoxic plenums" are devices which are claimed by a Dr. Kevin Novak to remove nitrogen from an aquarium by converting ammonia to nitrogen gas in anoxic conditions. The Biocenosis Clarification Basket reactors are simply mixtures of kitty litter and laterite gravel placed either in a porous plastic basket - [8.8.1. Sizing Filters in Depth](https://aquariumscience.org/8-8-1-sizing-filters-in-depth/): Aquarium size is actually pretty useless to determine the number or size of fish an aquarium can stock or to size filters. Biofiltration surface area per metabolic pound of fish is much more useful. Calculations say that each metabolic pound of fish needs, in very general terms, 5 square feet of effective biomedia surface ABSOLUTE - [8.8. Filter and Media Design](https://aquariumscience.org/8-8-filter-and-media-design/): An illustration is in order. If we have a heavily stocked aquarium (one pound of fish) and are using static K1 media for our filter, how big does a canister filter need to be at one month of operation? For this calculation we need a table: This table show the options available: It is important - [8.9. Anaerobic Reactors](https://aquariumscience.org/8-9-anaerobic-reactors/): There are some commercial reactors (i.e. Aquaripure) for sale which claim to reduce nitrates in the aquarium to nitrogen gas (NO3 -> N2). Then there are several do it yourself designs of "anaerobic reactors". In a nutshell, these denitrifying reactors simply do not work and cannot work. The complete explanation of why this is is - [8.7.5. DIY Bottle Filters](https://aquariumscience.org/8-7-5-diy-bottle-filters/): Another filter made famous by Joey Mullens (the very knowledgeable and immensely likeable “King of DIY”) is a bottle filter. It has many variations but in its simplest form it is an 16-ounce inverted water bottle with an air tube from an air pump inserted in the neck, some foam over the spout, and holes - [8.7.4. Diatomaceous Earth Filters](https://aquariumscience.org/8-7-4-diatomaceous-earth-filters/): One enterprising aquarium hobbyist on YouTube was setting up to use a diatomaceous earth pool filter on his aquarium. His was going to use a small aquarium pump to power a relatively large pool filter. This was just kind of humorous. Pool pumps are large and powerful as that is needed to hold the diatomaceous - [8.7.3. Hamburg Matten Filter](https://aquariumscience.org/8-7-3-hamburg-matten-filter/): This is a sponge filter marketed by Swiss Tropicals called the Hamburg Matten filter (HMF). The simplest version is called the "Mattenfilter" by Swiss Tropicals and is simply an an air lift tube with a piece of thick urethane foam designed to go across the entire width of the aquarium. This "across the tank" option - [8.7.2. High Performance Filters](https://aquariumscience.org/8-7-2-high-performance-filters/): . Some folks are enamored by what is called a “bead” filter (Aquadyne) or, euphemistically, a "high performance filter" (got to love the marketing folks). It is NOT a bead filter, it doesn’t use beads! And it is not a "high performance filter". This filter is about $1,100 (i.e. incredibly expensive) for what is a - [8.7.1. Sand Filters](https://aquariumscience.org/8-7-1-sand-filters/): Stationary Sand Bed Filters Public aquariums typically use very large stationary sand filters to do the mechanical and biological filtration. Because the public aquariums use a small sand volume to fish weight ratio (.e. a lot of fish for a small amount of sand), they must backwash these filters daily, typically on a computerized automatic - [8.7. Other Filters](https://aquariumscience.org/8-7-other-filters/): There are many types of filters which have been used in small quantities in some aquariums by some folks. I’ll review them in these chapters: 8.7.1. Sand Filters 8.7.2. "High Performance" Filters 8.7.3. Hamburg Matten Filters 8.7.4. Diatomaceous Earth Filters 8.7.5. DIY Bottle Filters 8.7.6. Small Filters 8.7.7. Bottom of Tank Matten 8.7.8. Small DIY - [8.6.6. Do-it-yourself Sumps](https://aquariumscience.org/8-6-6-do-it-yourself-sumps/): Commercially available filter sumps are expensive, over $300. With addition of a pump and good biomedia the sump can come to over $500. Most people make their own sump filters using glass or acrylic aquariums 30% to 50% of the size of their main aquarium. One can Google Joey (the King of DIY aquariums) and - [8.6.5. Fluidized Beds](https://aquariumscience.org/8-6-5-fluidized-beds/): These sump filters use a polyethylene high surface area media (K1 micro, K1, Hel-X, etc.) in a fluidized moving bed set-up. This motion is well illustrated by this sump: Note the very important circular movement of the K1 media in the sump. It is important to note the following. . Many millions of dollars of - [8.6.4. Wet-Dry Filters](https://aquariumscience.org/8-6-4-wet-dry-filters/): Wet-dry filters are a hybridized version of the trickle sump filter where some submerged static biomedia is added. This gives better biofiltration than a trickle filter but is still only about 70% as efficient as a static media submerged bioballs filter. A 100% bioballs wet dry sump will have only about 10% of the efficiency - [8.6.3. Trickle Filters](https://aquariumscience.org/8-6-3-trickle-filters/): One type of sump filter is called a trickle filter. In a trickle filter the water flows into a tray with many small holes in it. The tray spreads the water out over a square foot or so of surface. This tray is over what typically is several gallons of some sort of bioballs which - [8.6.2. Static Sump Filters](https://aquariumscience.org/8-6-2-static-sump-filters/): Static submerged media sump filters are simply sumps filled with both water and a biomedia through which the water flows. Most sump filters in the hobby are static submerged media sumps. These are like all submerged media filters in that the load of fish they can successfully filter is dependent on the media that one - [8.6.1. Sumps in Depth](https://aquariumscience.org/8-6-1-sumps-in-depth/): The people who are serious about the hobby and have large aquariums use a sump filter in a large acrylic box or glass aquarium, typically located below the aquarium in the cabinet. This box typically has three basic sections (often the middle section is partitioned into several sub-sections). The first section of this filter is - [8.6. Sump Filters](https://aquariumscience.org/8-6-sump-filters/): The people who are serious about the hobby and have large aquariums use a sump filter, typically located below the aquarium in the cabinet. Sumps have many advantages. Many come on social media and ask "Sump or canister for my new 150 gallon tank?". The advantages are: Sumps hold tons more biomedia (think crystal clear, - [8.5.1. Under-Gravels in Depth](https://aquariumscience.org/8-5-1-under-gravels-in-depth/): A Caveat Undergravel filters have not been widely tested as a filter in the aquaculture industry, The limited testing done on gravel filters for aquaculture was "all over the map" due to the very high loading of commercial operations. So one is left with common sense and anecdotal "testing" as the only sources of information - [8.5. Under Gravel Filters](https://aquariumscience.org/8-5-under-gravel-filters/): . A Caveat Undergravel filters have not been widely tested as a filter in the aquaculture industry, The limited testing done on gravel filters for aquaculture was "all over the map" due to the very high loading of commercial operations. So one is left with common sense and low load testing by the author as - [8.4. Sponge Filters](https://aquariumscience.org/8-4-sponge-filters/): Sponge filters are probably the least expensive filter. Sponge filters typically are holed cylinders of gray foam about four to six inches in diameter and four to eight inches tall with an air tube coming out the top. To operate this filter air is pumped into an airlift tube to draw water through the sponge. - [8.3.2. Do-it-yourself Canisters](https://aquariumscience.org/8-3-2-do-it-yourself-canisters/): Joey (the King of DIY aquariums) has a YouTube Video on making a do-it-yourself pipe canister filter. His was about four-foot-long and made from 4-inch pipe. This will give you about 2.6 gallons or 10 liters of room for media. Leaks can be a huge problem with Joey’s design (or any DIY canister design). If - [8.3.1. Canisters in Depth](https://aquariumscience.org/8-3-1-canisters-in-depth/): The biggest myth with canisters is that the flow through the canister is what is important. That is just plain incorrect. The test below showed that flow has very little effect on the efficiency of a canister. Test of Flow Rate in Canisters Canisters are normally rated by their flow rate. Supposedly if you double - [8.3. Canister Filter](https://aquariumscience.org/8-3-canister-filter/): One Big Scam Any discussion of ANY filter requires a disclaimer. ALL commercial filters almost without exception tell the owner to replace the filter media (Sponge, ceramic rings, carbon, Matrix, etc.) on a regular basis: once a month, once every three month or once every six months. Supposedly this is because the media becomes clogged - [8.2. Hang-on-the-back Filters](https://aquariumscience.org/8-2-hang-on-the-back-filters/): There are many types of filters which use a box hung off the back of the aquarium to mechanically filter the waste. These are called hang-on-back, HOB or cartridge filters. They range from $20 to $90. They are probably the most common filter. Most HOB filters move the water from one side (the side away - [8.1. Review of Filters](https://aquariumscience.org/8-1-review-of-filters/): By the simplified version there are many types of filters used for the tropical aquarium which can be scored by approximate number of three inch fish the filter will support, media capacity, ease of cleaning, cost, and appearance: *# of 3" Fish refers to the number of three inch fish that can be given crystal - [8. Review of Aquarium Filters](https://aquariumscience.org/8-review-of-aquarium-filters/): One Big Scam Any discussion of ANY filter requires a disclaimer. ALL commercial filters almost without exception tell the owner to replace the filter media (Cartridges, sponge, ceramic rings, carbon, Matrix, etc.) on a regular basis, once a month, once every three month or once every six months. Supposedly this is because the media becomes - [7.5. Denitrifying Media](https://aquariumscience.org/7-5-denitrifying-media/): Many people make the claim that their nitrates went down significantly after six to ten months of using Biohome Ultimate™ or De*Nitrate™ (a smaller sized Matrix), the two main media claiming to do anaerobic decomposition of nitrate to nitrogen. The familiar refrain is: “After six months my nitrate levels had gone down from 80 to - [7.4.7. Poly-Filter](https://aquariumscience.org/7-4-7-poly-filter/): Poly-Filter is an extremely expensive ($45 for a one square foot piece!) fibrous pad material which is commonly used in filters. Some breeders add this to the bags of fish shipments, supposedly to absorb or adsorb contaminants. It supposedly removes “Harmful Organics, Toxic Ammonia and Nitrite, Heavy Metals, All Forms of Phosphate, Medications after Treatment”. - [7.4.5. Phosphate Remover](https://aquariumscience.org/7-4-5-phosphate-remover/): Phosphate removing granules work! Iron and aluminum phosphates are simply very insoluble. So, these products will remove phosphates from the water. The use of phosphate removing granules are indicated where a phosphate test indicates high phosphates are causing an algae bloom. "Blue-green algae" blooms are very commonly caused by high phosphate in the water. So - [7.4.4. Zeolite](https://aquariumscience.org/7-4-4-zeolite/): There is a mineral which selectively removes ammonium from the water. It is a zeolite called clinoptilolite. This can be found in the LFS as white granules. This material can remove about 1.74 mg NH4–N g−1 (“Ammonia Removal from Leachate solution using Natural Chinese Clinoptilolite”, Wang et. al. 2006). A 100-gallon aquarium with 3 part - [7.4.3. Ion-Exchange Resins](https://aquariumscience.org/7-4-3-ion-exchange-resins/): There are two distinct uses for deionizing resins. One is to treat water for a water change and one is to directly treat the aquarium water to remove nitrates or ammonia. Neither use is a very good use of monetary resources, to put it mildly. What is DI (Deionizing or Ion Exchange) resin? From Wikipedia: - [7.4.2. Activated Carbon](https://aquariumscience.org/7-4-2-activated-carbon/): The activated carbon used in aquarium filters is elemental carbon, i.e. pure carbon with nothing else in the atomic structure. Activated carbon is typically lignite coal heated above the temperature at which it burns in an oxygen-free atmosphere. Since there is no oxygen, the carbon of the coal doesn’t burn. Instead there are a billion - [7.4. Chemical Filtration Media](https://aquariumscience.org/7-4-chemical-filtration-media/): The "Snake Oil" Called Chemical Filtration All the "experts" from the aquarium supply companies recommend expensive chemical filtration as the third step to filtration. This is ALL just a profit making scam that has been perpetrated on the hobby for over fifty years. "Expert recommendations" and "science" do not go hand in hand due to - [7.3. Media Volume](https://aquariumscience.org/7-3-media-volume/): If one works all the numbers on biofiltration media in the aquarium filter you come up with two very interesting tables on the basis of volume (cubic inches). The first volume table is based on the well established fact that ammonia oxidation needs 5 square feet of effective biomedia surface area per metabolic pound of - [7.2.13. Clay Balls](https://aquariumscience.org/7-2-13-clay-balls/): If one is absolutely enamored of the ceramic media approach expanded clay pebbles are a cheap way to go. This media is used for hydroponics and growing orchids. It is cheap, anywhere from one to $1 to $2 per liter. This product has a low effective surface area of 20 FT2/FT3. As such this product - [7.2.12. Matrix](https://aquariumscience.org/7-2-12-matrix/): Seachem Matrix is a "natural rock" product that is heavily marketed by Seachem as a supposedly extremely good media to be put into aquarium filters. Matrix is NOT good media for aquarium filters. It has the following shortcomings: Low effective surface area which gives poor biofiltration Sheds small abrasive particles which take out pumps Does - [7.2.10. Growstone](https://aquariumscience.org/7-2-10-growstone/): There is a product which used to be available over the internet which was occasionally used as a biomedia. It was called "Growstone". The name was changed to "Buddystone" in 2019 This is a fused glass product with a size of approximately 3/8 inch. This is recycled glass from the landfill and it absorbs water - [7.2.8. Pot Scrubbers](https://aquariumscience.org/7-2-8-pot-scrubbers/): Pot scrubbers have the best combination of biofiltration capability, ease of use and availability of any biomedia. Extensive testing has shown it to be a very good media to put in an aquarium filter. If one is a nerd like the author one might be interested in this long boring article on why this is - [7.2.7. Bio Balls](https://aquariumscience.org/7-2-7-bio-balls/): Bio balls have a moderately low surface area which make them one of the less efficient biomedia for submerged filters. This was confirmed by a test run on the ammonia oxidizing capability of various filter media. Bio balls did not perform very well in this test. The only good use for bioballs is as a - [7.2.6. PP EVA Pads](https://aquariumscience.org/7-2-6-pp-eva-pads/): There are a whole series of bonded semi-rigid fiber mats or pads sold for filtration. The very coarse open pads are made of polyester fibers, PP (polypropylene) or EVA (ethylene vinyl acetate) plastic. Matala pads and Japanese mats are probably the two versions used most. Their cost is $40 to $80 per cubic foot and - [7.2.5. Gravel](https://aquariumscience.org/7-2-5-gravel/): Small aquarium gravel turns out to be a reasonably good filter media. If one fills a canister with bags of cheap aquarium gravel the canister will be a much better filter than say a canister filled with expensive ceramic media. This is very surprising but it is true! Considering that small gravel can be sometimes - [7.2.4. Pumice Perlite](https://aquariumscience.org/7-2-4-pumice-perlite/): Pumice is a form of natural volcanic rock where a very low viscosity lava shot to the Earth’s surface full of gas. The gas expanded rapidly at the surface before the molten rock could cool. The rock thus became a very lightweight foam. This foam is dug up, crushed and sorted to various sizes. Pumice - [7.2.3. K1 Media](https://aquariumscience.org/7-2-3-k1-media/): K1 is a chopped plastic media that is used both in something called a "fluidized bed sump" (or a "moving bed bioreactor" or MBBR) and used as a static (i.e. "stationary and unmoving") media in other aquarium filters. The ability of fluidized K1 to biofilter the water and give crystal clear, very healthy water is - [7.2.2. Foam Media](https://aquariumscience.org/7-2-2-foam-media/): Foam is simply the best biomedia to put in any static aquarium filter. The ability of foam to biofilter the water and give crystal clear, very healthy water is simply the best of any static media. The only "more effective" media than 30 ppi foam is fluidized bed K1 media. On a cubic inch of - [7.2.1. Polyester Floss](https://aquariumscience.org/7-2-1-polyester-floss/): Polyester Floss is usually only used for mechanical filtration. It is rarely used for biofiltration. This article goes into why polyester floss has to be used this way. Polyester fibers are used in three distinct types of filtration: Mechanical filtration (very common) Polishing filtration (often tried but rarely succeeding) Biofiltration (rare) Poly-fil (polyester filter floss) - [7.2. Individual Media List](https://aquariumscience.org/7-2-individual-media-index/): This is an index of pages devoted to all the various filter media in use in filters. Each article discusses each media type in depth: 7.2.1. Polyester Floss 7.2.2. Foam and Sponge 7.2.3. K1 Media 7.2.4. Perlite and Pumice 7.2.5. Aquarium Gravel 7.2.6. PP and EVA Pads 7.2.7.Bio Balls 7.2.8. Pot Scrubbers 7.2.9. Lava Rock - [7.1.2. Media Function](https://aquariumscience.org/7-1-2-media-function/): Biofiltration media are the material put into the filters to act as surfaces for the growth of beneficial bacteria. When discussing biofiltration media the important guideline to remember is: . One Pound of Fish Needs 100 Square Feet of Biomedia Surface Area to have Crystal Clear Healthy Water . All biomedia need to be judged - [7.1. Review of Media](https://aquariumscience.org/7-1-review-of-media/): The first consideration when choosing a filter media is the ammonia oxidizing capability of the media. Filter Media Ammonia Oxidizing Capacity Three tests (24 ninety day runs total) of the ammonia oxidizing capability of various filter media were run. All three tests correlated remarkably well. The tests gave an "efficiency" number for various aquarium filter - [6.8. Thorough Cleaning](https://aquariumscience.org/6-8-thorough-cleaning/): Both beginners and experienced aquarium owners often make a big mistake which stresses fish in their aquarium. They give their new filters a thorough cleaning at the end of cycling. Or they clean their filters thoroughly once a month. And their water then gets very cloudy and they get ammonia spikes. A thoroughly cleaned aquarium - [6.7. Nitrate Factory](https://aquariumscience.org/6-7-nitrate-factory/): One myth that must be put to rest is the concept of a “nitrate factory”. Well meaning but ill-informed commentators on social media very commonly dismiss this filter or that filter as “nitrate factories”. When pressed for an explanation of “nitrate factories” they don’t reply. There is one simple truth: . All Good Filters are - [6.6. Aquaponic Filtration](https://aquariumscience.org/6-6-aquaponic-filtration/): Aquaponic filtration uses plants to remove nitrates from the water. It is very misunderstood. Each small fish needs a lot of rapidly growing plant tissue to adequately remove the nitrates the fish puts out. A moderately stocked aquarium will NOT be adequately bio filtered by one pothos plant on top of the aquarium. The Basic - [6.4.2. Polishing Filtration](https://aquariumscience.org/6-4-2-polishing-filtration/): The term “polishing filtration” is often used in the aquarium hobby. It is the filtration of small visible particles in the water by a very fine mechanical filter such as packed polyester floss. Well packed polyester floss (“Polyfil” the material used in pillows) will take out particles one can see. This will give "somewhat" clear - [6.4.1. Crystal-Clear Water in Depth](https://aquariumscience.org/6-4-1-crystal-clear-water-in-depth/): This is an in depth analysis of how and why to obtain crystal clear water. It is only for real nerds like the author. Crystal clear water is, in general, the product of several factors: At least 100 square foot of biomedia surface area per pound of fish A reasonable turnover rate in the aquarium - [6.4. Crystal-Clear Water](https://aquariumscience.org/6-4-crystal-clear-water/): Perfectly clear, indeed sparkling crystal-clear, water is the nirvana of any aquarium owner. This factor is difficult to quantify. But all experienced aquarium owners know what crystal-clear water is. It is just something you know when you see it. If you watch the aquarium YouTube or Facebook videos only roughly one in ten of the - [6.5.1. Flow Function](https://aquariumscience.org/6-5-1-flow-function/): One of the biggest myths in the hobby is that flow and turn-over rate is important. If I have two Sunsun 304s on a tank with two plastic pot scrubbers in each filter turning over the water 6X per hour, will this be better than one Sunsun 304 filled with forty plastic pot scrubbers and - [6.5. Water Flow Rate](https://aquariumscience.org/6-5-water-flow-rate/): One of the biggest myths in the aquarium hobby is that a canister which has an actual flow rate of 600 GPH (gallons per hour) can filter roughly twice the amount of fish that a canister that has an actual flow rate of 300 GPH. In actuality the 600 GPH canister might be 10% better - [6.2.3. Cloudy Water](https://aquariumscience.org/6-2-3-cloudy-water/): Cloudy Water in the Aquarium Many people have their water turn cloudy, often looking like someone poured milk into the aquarium. Another term for this is a "bacterial bloom". The term “bacterial bloom” is a bit of a misnomer. Initially it can be just bacteria clouding the water. But then over the course of a - [6.2.2. Brown Gunk](https://aquariumscience.org/6-2-2-brown-gunk/): Terminology The "brown gunk" found in aquarium filters is all a type of aggregate called a "biofilm"; a matrix or gel of polysaccharides and proteins with bacteria, protozoans, fungi and water molds. For purposes of this article the thin outer surface of the "brown gunk" we will call a "biofilm". The interior of the "brown - [6.2.1. Detritus Explained](https://aquariumscience.org/6-2-1-detritus-explained/): The Science of "Detritus" In the eyes of most hobbyists "detritus" is any "brown gunk" in an aquarium. Other words used to describe this material is mulm, organic matter, sludge and debris. The subject of biofiltration in an aquarium is very dependent on the subject of “detritus”. In biology, detritus is particulate organic material, normally - [6.2. Biofiltration](https://aquariumscience.org/6-2-biofiltration/): The most important part of an aquarium's filtration is what goes on at the microscopic level. This is so called biofiltration. It is the world of bacteria and micro-organisms that can’t be seen with the naked eye. This biofiltration is the key to good water chemistry, good fish health and crystal-clear water. We will cover - [6.1.2. Uncleaned Mechanical Filtration](https://aquariumscience.org/6-1-2-uncleaned-mechanical-filtration/): This concept is where a hobbyist doesn’t clean the mechanical filter on a regular basis. Instead they let the solid feces and uneaten food just naturally decompose in a biofilter which acts as an "uncleaned" mechanical filter. If the component is cleaned weekly or so it is defined as a "cleaned" mechanical filter. Almost all - [6.1.1. Cleaned Mechanical Filtration](https://aquariumscience.org/6-1-1-cleaned-mechanical-filtration/): The basic concept here is to remove as much solid feces and uneaten food as possible before it degrades and fouls the water with nitrogen in the form of ammonia. This will reduce the ammonia and nitrate load to the aquarium by roughly 5% to 10%. The key identifying property with mechanical filters in the - [6.1. Mechanical Filtration](https://aquariumscience.org/6-1-mechanical-filtration/): Mechanical filtration in an aquarium is the removal of particles the hobbyist can see. These particles include fish feces and uneaten food. This is what most beginners think is the most important type of filtration. Mechanical filtration has some complicated effects. If one has poor biofiltration, mechanical filtration takes on some importance. But mechanical filtration - [6. Filtration](https://aquariumscience.org/6-filtration/): Definitions Conventional wisdom recognizes three type of filtration: Mechanical filtration is the removing from the water column of particles one can see, i.e. very roughly those particles over 100 microns (0.004 inches) in size Chemical filtration is the removal of some colored organics and some smells from aquarium water Biofiltration is filtration by living organisms - [18.6. Old Tank Syndrome](https://aquariumscience.org/18-6-old-tank-syndrome/): "Old tank syndrome" is a tank with Low KH (80) in unplanted tank High ammonia readings (>4) Typically the fish get lethargic and stop eating. This can be the phenomenon of "old tank syndrome". Note that "old - [5.5.3.1. Ammonia Detoxifying](https://aquariumscience.org/5-5-3-1-ammonia-detoxifying/): When one neutralizes the chlorine in a water supply with chloramine in it, there is ammonia left over. There are a whole series of products which claim to “detoxify” this ammonia at the same time as removing the chlorine. Some of these products are sold largely to "detoxify" ammonia during cycling and when aquariums do - [5.5.2.1. Ammonia in Chloramine](https://aquariumscience.org/5-5-2-1-ammonia-in-chloramine/): Chloramine (generally monochloramine NH2Cl) is a combination of chlorine and ammonia used in many municipal tap water suppliers to remove bacteria from the water. The molecular weight of NH2Cl is 51.5. The molecular weight of NH2 is 16. So the amount of chloramine is roughly three times (51.5/16) the amount of ammonia measured. If you - [5.5.2. Chloramines](https://aquariumscience.org/5-5-2-chloramines/): Chloramine (generally monochloramine NH2Cl) is a combination of chlorine and ammonia used in many municipal tap water suppliers to remove bacteria from the water. Chloramines are less prone to dissipation by long runs of piping and is considered less of a carcinogen than chlorine. Chloramine does not kill bacteria firmly ensconced in a biofilm on - [5.5.1. Chlorination in Depth](https://aquariumscience.org/5-5-1-chlorination-in-depth/): Most municipal water supplies in the developed world use chlorine to make the water safe to drink. The author spent several weeks close to death after brushing his teeth with poorly chlorinated water from a municipality in the “undeveloped” world, so he will tell you chlorination is a very good and necessary thing. Chlorine Removers - [5.5. Chlorine and Chloramine](https://aquariumscience.org/5-5-chlorine-and-chloramine/): Roughly 98% of all municipal water supplies in the US have chlorine or chloramine added to the water. This chlorine is added to kill bacteria in the water. If this wasn't done, people would get waterborne diseases. The author spent several weeks close to death after brushing his teeth with poorly chlorinated water from a - [5.4.1. Nitrate in Depth](https://aquariumscience.org/5-4-1-nitrate-in-depth/): Predicate All discussions of research papers on nitrate must be predicated with a caution. The 10 ppm of nitrate (NO3-N) of the scientists, (the Hach test kit and the Lamotte test kit) is a 44 ppm test level of nitrate (NO3) via the "normal" aquarium test kits (API aquarium test kit, the Seachem Multitest kit, - [5.4. Safe Nitrate Levels](https://aquariumscience.org/5-4-safe-nitrate-levels/): Predicate All discussions of nitrate must be predicated with a caution. The 10 ppm of nitrate of the scientists, (the Hach test kit and the Lamotte test kit) is a 44 ppm test level of nitrate via the "normal" aquarium test kits (API aquarium test kit, the Seachem Multitest kit, the Sera Nitrate test, the - [5.3.2. Nitrite in More Depth](https://aquariumscience.org/5-3-2-nitrite-in-more-depth/): The recommended chronic exposure upper limit in the aquarium of nitrite in parts per million is dependent on pH as follows (from Duke University https://users.cs.duke.edu/~narten/faq/cycling.html): These limits are for chronic toxicity, where long term damage to internal organs occurs. There are some university papers on the toxicity of nitrites. “Acute Toxicity of Ammonia and Nitrite - [5.3. Safe Nitrite Levels](https://aquariumscience.org/5-3-safe-nitrite-levels/): Nitrites are products of the decomposition of food proteins. Nitrite is not a poisonous as many would have us believe. The acute toxicity is where the fish die in hours or days. This is the “Toxic” level in the chart below. The chronic toxicity is where the fish will have diseases and a general “failure - [5.2.1. Ammonia in Depth](https://aquariumscience.org/5-2-1-ammonia-in-depth/): We are going to predicate this article with a warning: . The ammonia level per the API test should always be 0.25 or lower, not because ammonia is that toxic, but rather because any ammonia indicates poor biofiltration which will kill fish from excess bacteria in the water. . If one has a new aquarium - [5.2. Safe Ammonia Levels](https://aquariumscience.org/5-2-safe-ammonia-levels/): We are going to predicate this article with a warning: . The ammonia level per the API test should always be 0.25 or lower, not because ammonia is that toxic, but rather because any ammonia indicates poor biofiltration which will kill fish from excess bacteria in the water. . If one has a new aquarium - [4.9. Un-bagging Fish](https://aquariumscience.org/4-9-un-bagging-fish/): If one is unbagging fish from a fish store an hour or two from your house the method of unbagging you use is immaterial. You can cut open the bag immediately and simply "cut, pour, plop" into your quarantine aquarium, or you can use any one of many “gradual acclimatization schemes” that can be found - [4.8. "Stability" isn't Important](https://aquariumscience.org/4-8-stability-isnt-important/): The going mantra is that tropical fish require "stability" and “constancy” of pH and temperature. Supposedly any rapid change over 0.2 pH or 2 degrees F. temperature will “shock”, “stress” and possibly kill the fish. This idea is simply a myth, one of the many myths passed down by generations of aquarium owners. It is - [4.7. Fish Tolerance to pH](https://aquariumscience.org/4-7-fish-tolerance-to-ph/): One common myth of fishkeeping is that generations in captivity have created strains of fish more tolerant of temperature, pH and hardness excursions. If the temperature, pH and hardness in the breeding aquariums were pushed to the limit so that only two to four fish from each batch of fry survived and this was continued - [4.6. Salts in the Water](https://aquariumscience.org/4-6-salts-in-the-water/): The “salt” (elemental) analysis of different biotope waters can be left to the perfectionists among us. They aren’t that important unless you are using RO water or distilled water. RO Water RO (reverse osmosis) water does typically need some addition of salt. This is to provide freshwater fish with the osmotic pressure that allows them - [4.5.1. General Hardness](https://aquariumscience.org/4-5-1-general-hardness/): General hardness, GH, in the water basically reflect the amount of the elements Calcium and Magnesium one has in the water. Calcium and Magnesium is what forms scale and crusts in your toilet and bathtub tiles (and your aquarium). Calcium and Magnesium are elements which don’t dissolve very well in water. So, when given the - [4.5. Water Hardness](https://aquariumscience.org/4-5-water-hardness/): Like all the topics in this website we discuss water hardness in a series of discussions. The simplest explanation is first, followed by a more in depth discussion. Then there are links to very in depth discussions of both GH and KH hardness. The Simple Explanation There are two types of hardness use in the - [4.4.3. Carbon Dioxide and pH](https://aquariumscience.org/4-4-3-carbon-dioxide-and-ph/): Carbon dioxide is rarely a factor in most fish only aquariums. Where it is slightly important in a fish only aquarium is in the consideration of pH. The various relationships of carbon dioxide in the aquarium is a very convoluted chemical dissertation best left to the obsessive compulsive among us. Read on only if you - [4.4.2. Buffering the Water](https://aquariumscience.org/4-4-2-buffering-the-water/): Simply put buffering is the ability of water to resist changes in pH. Many people comment about the importance of a stable pH and having a buffered system. The importance of pH is vastly overrated as aquarium product suppliers want to sell the unsuspecting newcomer a bunch of "pH Up", "pH Down", "Malawi Buffer" or - [4.4.1. Aquarium pH is Not Important](https://aquariumscience.org/4-4-1-aquarium-ph-is-not-important/): Beginners to the aquarium hobby tend to obsess about things like pH. The simple fact of the matter is that pH just isn't very important. And pH swings, even very rapid ones, are harmless to fish. This is a long and boring analysis which will only be of interest to real nerds like the author. - [4.4. Aquarium pH](https://aquariumscience.org/4-4-aquarium-ph/): Aquarium water pH is simply not very important. MYTHBUSTER: . Most fish have a large tolerance range when it comes to pH. And all fish accept very wide and sudden changes in water pH quite readily. . The Simple Explanation of pH Most folks make pH very complicated, with terms like “logarithmic” and “hydrogen ion”. pH - [4.3. Free Floating Bacteria](https://aquariumscience.org/4-3-free-floating-bacteria/): One very overlooked aspect of water chemistry is the number of bacteria found in the water of the aquarium. The bacterial water count is probably the most important part of keeping a fish healthy in an aquarium. All fish are healthier in water which is very clean, with very few bacteria in it. Note that - [4.2. Aquarium Temperatures](https://aquariumscience.org/4-2-aquarium-temperatures/): The temperature of an aquarium is much less important than hobbyists give it credit for. Most freshwater tropical fish live quite comfortably at the temperature of most homes (650 to 850 F, 180 to 300 C). And, contrary to popular mythology, temperature fluctuations do not hurt tropical fish. In nature the temperature of layers of - [4.1. Importance of Water](https://aquariumscience.org/4-1-importance-of-water/): Probably the biggest myth out there is that tropical fish need close attention to temperature, pH, GH and KH. Almost all tropical fish do very well between 70 and 90 degrees and 6.5 to 8.5 pH. The water parameters KH and GH (i.e. “hardness”) are completely unimportant unless you are breeding blackwater fish or doing - [4. Temperature, pH, KH and GH](https://aquariumscience.org/4-temperature-ph-kh-and-gh/): The water fish swim in is very important, obviously. But it is not nearly as important as people give it credit for. The chemistry of the water, the pH, the hardness and the salts contained in the water, are just not very important to the well-being of the fish. Most tap water between a pH - [3.8. Food and Malawi Bloat](https://aquariumscience.org/3-8-food-and-malawi-bloat/): There is a disease of African cichlids called “Malawi bloat”. This is a form of bloat common in a type of fish from Lake Malawi in Africa called a mbuna cichlid. This is the same disease as the bloat we discuss elsewhere under “Diseases”. To see that discussion go to the following link: 11.3. Malawi - [3.7. Banned Fish Food](https://aquariumscience.org/3-7-banned-fish-food/): This is a very long and boring article which will only be of interest to the real nerds, like the author is. Social Media Advice on Food The well meaning but ill-informed individuals on social media have decided the following foods are never to be fed to tropical fish or to only be fed occasionally: - [3.6.1. Dry Fish Food in Depth](https://aquariumscience.org/3-6-1-dry-fish-food-in-depth/): A Predicate The most important variable when choosing a commercial dry food is the protein level. The higher the protein level in any food the healthier the fish. But this effect is NOT because eating high protein food is good for a fish. Rather the effect is due to what high protein food can do - [3.6. Dry Fish Food](https://aquariumscience.org/3-6-dry-fish-food/): A Caveat Protein Level in the Food The most important variable when choosing a commercial dry food is the protein level. The higher the protein level in any food the healthier the fish. But this effect is NOT because eating high protein food is good for a fish. Rather the effect is due to what - [3.5. Breaking Up Food](https://aquariumscience.org/3-5-breaking-up-food/): It is important that food be distributed widely in the water flow of the tropical fish aquarium and not just put in as a large clump. This is especially true with cichlids. If food is put in as a clump one dominant fish can monopolize the clump and not allow others a lot of access - [3.4. Gel Fish Food](https://aquariumscience.org/3-4-gel-fish-food/): The food I used for my fish is a homemade high protein gel fish food. I find this to be the healthiest food there is as the protein level is very high, >55% by dry weight. The Mazuri gel food is also excellent. Many hobbyists like to make their own food. So here is one - [3.3.1. Amount in Depth](https://aquariumscience.org/3-3-1-amount-in-depth/): Over Feeding Since fish are cold blooded (poikilothermic), they do not require a lot of energy and food to survive compared to mammals. Overfeeding your fish can lead to problems. It leads to excess waste which will cause the biological load on the filtration system will become overworked. Continued overload can lead to the disruption - [3.3. Amount of Fish Food](https://aquariumscience.org/3-3-amount-of-fish-food/): What I recommend for feeding is simple; . Feed fish once a day ONLY an amount of food the fish can consume in one minute. . If there is food still in the aquarium after one minute you need to cut back on the amount. The amount of fish food to add used to be - [3.2. Fish Diet Specializations](https://aquariumscience.org/3-2-fish-diet-specializations/): Researchers in some 13 books I read on animal nutrition have found that ALL juvenile fish need four things in their food for optimal growth a protein level of at least 40% and preferably over 50% a fat level of at least 10% that two of the first three ingredients be either "whole fish" of - [3.1. Insignificance of Food](https://aquariumscience.org/3-1-insignificance-of-food/): A Caveat Protein Level in the Food The most important variable when choosing a fish food is the protein level. The higher the protein level in any food the healthier the fish. But this effect is NOT because eating high protein food is good for a fish. Rather the effect is due to what high - [3. Fish Food](https://aquariumscience.org/3-fish-food/): A Caveat: Protein Level in the Food The most important variable when choosing a fish food is the protein level. The higher the protein level in any food the healthier the fish. But this effect is NOT because eating high protein food is good for a fish. Rather the effect is due to what high - [2.5. Aquarium Fish-in Cycling](https://aquariumscience.org/2-5-aquarium-fish-in-cycling/): If one has fish in the aquarium during cycling the tank, this is called "fish-in cycling". I don't recommend fish-in cycling. There is simply no reason to do it. The only benefit is that doing it in its simplest form is very easy (doing it in its more complicated form is very difficult). But often - [2.8. Bacteria-in-a-bottle](https://aquariumscience.org/2-8-bacteria-in-a-bottle/): There are a whole series of "quick start", "starter bacteria", "nitrifying bacteria", "stabilization systems" and "bacteria-in-a-bottle" products that claim to enable one to do the following: "Add Fish Immediately" "Safe Immediate Introduction of Livestock" "Allows Instant Addition of Fish" "Avoid New Tank Syndrome" "Prevents New Tank Syndrome" "Rapidly Cycle Tanks" "Allows Immediate Introduction of Fish" - [2.7. New Tank Syndrome](https://aquariumscience.org/2-7-new-tank-syndrome/): Pet stores want to make money selling fish, so they often sell novice hobbyist a lot of decent-sized fish with the new aquarium they have purchased. The novice sets up the aquarium, puts in the water with some chlorine neutralizer, and adds a sizable number of fish. As is normal with a novice, they feed - [2.11. Inoculate for Cycling](https://aquariumscience.org/2-11-inoculate-for-cycling/): The bacteria which convert toxic fish pee to a non-toxic substance are called "beneficial bacteria". Let us put one persistent myth to bed right away. Beneficial bacteria ONLY grow on surfaces. They do not grow in the water column. So water from an established tank will not "significantly" "seed" beneficial bacteria into a new tank. - [2.10. Nitrogen Cycle](https://aquariumscience.org/2-10-nitrogen-cycle/): An understanding of the nitrogen cycle is NOT REQUIRED to have a good aquarium. This idea that every hobbyist needs to understand the nitrogen cycle is a myth promulgated by well meaning but ill-informed individuals on social media. But if one is interested in the nitrogen cycle one can read on. This is only for - [2.6. Not Cycling at All](https://aquariumscience.org/2-6-not-cycling-at-all/): Understand, I recommend fish-less cycling for all aquarium hobbyists setting up a tank. This is simply the best way to cycle an aquarium with the least risk to the fish. But contrary to many fervent people on social media, one does not HAVE to formally cycle a tank. If one only adds a few fish - [2.4. Cycling with Ammonia](https://aquariumscience.org/2-4-cycling-with-ammonia/): There are a huge number of beginner hobbyists that have Googled aquarium cycling and come up with ammonia as being the perfect feed for fishless (no fish in the tank) cycling. This is largely because of the determined efforts of one supplier (Dr. Tim) of very overpriced solutions of ammonium chloride. Most experienced hobbyists, including - [2.3. How I Cycle](https://aquariumscience.org/2-3-how-i-cycle/): I can only tell you what I do. There are very many ways to cycle an aquarium and they all seem to work well. But being an obsessive-compulsive chemist nerd, I’ve come up with what I feel gives the fastest possible cycling time where the tank is capable of handling a large load of fish - [2.2. Many Ways to Cycle](https://aquariumscience.org/2-2-many-ways-to-cycle/): There are many ways to successfully cycle an aquarium: The ammonia “feed” can be fish food, chopped meat, milk, baby food, chemical ammonia, ammonium chloride, or even urine. You can add a large amount of feed like a whole shrimp in a sock or you can add small amounts of “feed” over time. The beneficial - [2.1. Fish-less Cycling](https://aquariumscience.org/2-1-fish-less-cycling/): What is "Cycling"? In a nutshell, fish pee is a somewhat poisonous material (ammonia, that cleaning stuff that smells bad). This material is rendered harmless in an established aquarium by very slow-growing “beneficial bacteria” which grow ONLY on the surface of structures like biomedia and sponges in the filter. This process is called the "Nitrogen - [1.1. Aquarium Beginner Guide](https://aquariumscience.org/1-1-aquarium-beginner-guide/): The aquarium is a small ecosystem in which Mother Nature works her magic. And Mother Nature is very flexible and very forgiving. So when someone tells you "You must do blah blah" when you have an aquarium, ignore them. They don't know what they are talking about. The only firm rule in the aquarium hobby - [2. Aquarium Cycling](https://aquariumscience.org/2-aquarium-cycling/): “Cycling” is the term used in the aquarium hobby for the process which grows colonies of something called “beneficial bacteria”. Note that all these discussions define "beneficial bacteria" to include both ammonia oxidizing bacteria (AOBs) and ammonia oxidizing archaea organisms (AOAs). These "beneficial bacteria" convert toxic fish pee (ammonia) to a relatively innocuous compound called - [1.5. Aquarium Options](https://aquariumscience.org/1-5-aquarium-options/): There are about as many “correct” ways to keep fish thriving in an aquarium as there are aquarium keepers. It is not an exact demarcation. And Mother Nature is extremely flexible. But the aquarium options can be divided into six very broad options. Here are three "fish-only" aquarium options: . Easily 80% of the aquariums - [1.1.12.1. Guideline Example](https://aquariumscience.org/1-1-12-1-guideline-example/): So let’s look at a typical beginner hobbyist’s first aquarium and score it by the five criteria in the previous article. 1.1.12. How to Make Fish Thrive This beginner has a community aquarium with angelfish, blue gouramis, swords, platys, corys, neons, and zebra danios. If this beginner uses a reasonable break-in period for their aquarium - [1.3. False Marketing Claims](https://aquariumscience.org/1-3-false-marketing-claims/): There are many, many aquarium products marketed with misleading or simply false marketing claims. Since there is no "truth in advertising" legal requirement and this industry is completely unregulated, marketing hype and downright falsehoods are the norms. Indeed, it is unusual to find an aquarium supply or food that doesn't have inflated or just downright - [1.4. Sources of Data](https://aquariumscience.org/1-4-sources-of-data/): This is a rather long and involved, opinionated, editorial rant on the many information sources one can use to research the aquarium hobby and how they are almost ALL very unreliable. Read on only if you want to hear the verbose and boring opinions of a crusty old curmudgeon: Sources of Data: Most of the - [1.2. Falsehoods and Myths](https://aquariumscience.org/1-2-falsehoods-and-myths/): There are many dogmas, myths, misconceptions, misbeliefs, falsehoods, and phony religions promulgated in keeping tropical aquariums. Most are someone's opinion that one thing or another is going to damage the tropical fish and one shouldn't do it (whatever it is). This sort of negative naysaying is very easy to do and often very difficult to - [1. Aquarium Basics](https://aquariumscience.org/aquarium-basics/): What are just the bare basics of keeping a fish aquarium? This first chapter of the aquarium science website is a series of basic articles on what science has found out is the best way to set up a beginner's aquarium. This science points out that the aquarium is a natural system, a miniature Mother ## Categories - [General](https://aquariumscience.org/category/general/)