4.11. Tank Syndromes

Aquariums can exhibit three distinct aquarium syndromes: Old Tank, New Tank and Sick Tank

18.7. Sick Tank Syndrome

An aquarium with “perfect parameters” (ammonia 0, nitrite 0, nitrate 0) is often a very unhealthy aquarium.

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”. This is a “disease” that has probably never occurred in any aquarium. Water that is very cold can absorb much more air in solution than warm water. Say warm water (25 degrees C.) can … Read more

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 … Read more

12.10. The Shotgun Approach

When faced with a diseased aquarium fish it is often beneficial to hit the fish with a cocktail of several medications.

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 … Read more

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 … Read more

18.4. Cleaning a Filter

Filters need to be cleaned only when they plug up and the flow slows down. And even then they only need light cleaning.

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 … Read more

2.14. The Mature Aquarium

This article delineates how important it is to have a mature aquarium with a lot of biological diversity.

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 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 good … Read more

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

This is an article on how to set up an aquarium for dwarf aquarium shrimp and how to insure they prosper.

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 maker uses one … Read more

3.9. Fish Food and Gunk

The higher the protein content of a fish food the less brown gunk will be in an aquarium filter.

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 … Read more

2.13. Cycling Test

This article delineates some testing that was completely to establish how fast various aquarium cycling methods worked.

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”.

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 … Read more

12.7. Making Medicated Food

The concept of putting the medication in the food and not the water always raises howls of protest when presented. Internal fish diseases can ONLY be treated with medications in the food.

10.14. Fish Lice

Fish lice are found occasionally on tropical fish. This discusses how to get rid of them.

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: And all livebearers do well in a very wide range of water, contrary to popular mythology. We look at guppies first and then we look … Read more

6.9. Tap Water Rinsing

Probably the worst thing one can do to an aquarium filter is to put it under running water. Running water will rapidly clean out ALL the beneficial bacteria.

2.9. Instant Cycling Chemicals

There are a whole series of products which claim to “detoxify” ammonia and nitrite during cycling. They claim these products give an “instant cycle”. These claims are simply false marketing hype.

2.12. Beneficial Bacteria

“Beneficial bacteria” in an aquarium filter are largely responsible for changing somewhat toxic ammonia in fish waste to innocuous nitrate.

6.3. Over-filtration

Over-filtration is necessary in an aquarium in order to get healthy, bacteria free, crystal clear water

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 … Read more

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”, … Read more

17.2. Biotopes

Many ascribe to the concept of “biotopes”, where fish and plants from a certain region are grouped together. These biotopes are: There are many who try to set up aquariums per these biotopes. There are even competitions based on aquarium biotopes. Note that this can get very specialized. I’ve seen biotopes of only one particular … Read more

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 … Read more

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 … Read more

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 … Read more

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, … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read more

15.5. Aquarium Fertilizing

There are no less than seven methods used to fertilize plants in an aquarium. This article has links to all seven methods.

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 … Read more

15.3. Fish Limitations

It is challenging to have even moderate amounts of decent sized fish in a planted aquarium.

15.2. Fish

There are many types of small schooling fish which do very well in a planted aquarium.

14.9. Wavemakers

The selection and placement of wavemakers in an aquarium is reviewed in some depth.

14.4. Lights

Selecting the proper light for an aquarium can be somewhat challenging.

14.3. Rocks

All rocks found in a rock yard, stream,backyard or woods are perfectly safe in the aquarium with NO treatment.

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 … Read more

17.5. Goldfish

Goldfish are a very easy aquarium fish which will thrive even in small aquariums.

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, … Read more

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 … Read more

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.

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 … Read more

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 … Read more

12.5. Fish Don’t 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 … Read more

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 … Read more

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. Most … Read more

12.2. Treatments Summary

This article summarizes all the medicines which are useful in treating aquarium fish diseases.

12.1. Basics of Treatment

This article goes over the stock of fish medications; medications and scaleless fish; and medications and beneficial bacteria

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 two very distinct types of “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 … Read more

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 … Read more

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 … Read more

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. … Read more

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 … Read more

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, … Read more

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 … Read more

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 … Read more

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 … Read more

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.

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. … Read more

10.13. Pests

Some of the little critters found in aquariums discussed.

10.9. Anchor Worms

Anchor worms are small white worm-like crustaceans which are parasitic on fish.

10.11. Tapeworms

This is a discussion of the tropical fish disease known as tapeworms.

10.10. Black Spots

This is a discussion of the tropical fish disease called "Black Spot"

10.6. Flukes

Flukes cause problems with fish’s gills but are difficult to diagnose.

10.8. Lymphocystis

Lymphocystis is typically pink cauliflower like tumors that form on a tropical fish. They are caused by a virus and untreatable.

10.7. Fish Saprolegnia

Fish saprolegnia or fungus is a cottony white growth generally secondary to a bacterial infection.

10.12. Nematodes

There are two types of nematodes or roundworms which are common pathogens on aquarium fish: capillaria and camallanus.

10.5. Hexamita

Hexamita (often called internal parasites) can cause bloating, white poop, food spitting and refusal to eat. It is treated with metronidazole.

10.4. Fish Tuberculosis

Tuberculosis is probably the most common fish disease and few hobbyists even know the symptoms. Fish TB is best treated with added filtration and UV sterilization.

10.3. Bacterial

There are many ways that bacterial diseases present themselves in tropical fish.

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 … Read more

9.3. Air Stones

Airstone Aeration is very effective in the Aquarium, contrary to popular myth.

9.2. Turbulence and Aeration

Aeration in any aquarium is very dependent on the amount of “turbulence” that exists at the water air interface.

8.7. Other Filters

There are many types of filters which have been used in small quantities in some aquariums by some folks.

8.4. Sponge Filters

Sponge filters are an excellent filtration option for aquariums, especially breeding tanks.

8.3. Canister Filter

One Big ScamAny 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 and dirty. And the media … Read more

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 (7,5 cm) fish the filter will support, media capacity, ease of cleaning, cost, and appearance: *# of 3″ (7,5 cm) Fish refers to the number of three inch fish that … Read more

7.5. Denitrifying Media

Denitrifying media like Biohome and De*Nitrate simply do not work. They do NOT remove nitrate.

7.3. Media Volume

Calculating aquarium filter media volume requirements is relatively straight forward math problem.

7.1. Review of Media

For media inside any aquarium filter, foam, plastic pot scrubbers and K1 media were much better than ceramics, lava rock or pumice.

6.8. Thorough Cleaning

Aquarium filters should never be thoroughly cleaned. It removes most of the beneficial bacteria.

6.7. Nitrate Factory

The concept of aquarium filters being nitrate factories is an old myth. Nitrate Factories just cannot occur in any aquarium.

6.5. Water Flow Rate

The flow rate of an aquarium filter is much less important than social media would have us believe.

6.2. Biofiltration

An explanation of how biofiltration and beneficial bacteria work in an aquarium filter.

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. It is relatively unimportant. Filtration should be looked at from a chart. Obviously biofiltration is easily 80% of the game … Read more

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.

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 … Read more

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 … Read more

4.8. “Stability” isn’t Important

The going mantra is that tropical fish require “stability” and “constancy” of pH and temperature. Supposedly any rapid change will “shock”, “stress” and possibly kill the fish. This idea is simply a myth.

4.4. Aquarium pH

Most fish have a large tolerance range when it comes to pH, 6.5 to 8.5 pH. And all fish accept very wide and sudden changes in water pH quite readily

4.1. Importance of Water

If you can drink the water your fish will live in the water just fine. “Adjusting” the water parameters of an aquarium is simply a profit making scheme of some manufacturers

3.7. Banned Fish Food

There a a host of fish foods which are supposedly “bad for fish” which are actually very good for fish in an aquarium.

3.5. Breaking Up Food

When fish food is added to an aquarium it should be thoroughly dispersed throughout the aquarium.

2.7. New Tank Syndrome

“New Tank Syndrome” is a lot less common than social media will have you believe. But it can happen if a beginner adds too many fish and/or feeds them too much.

2.6. Not Cycling at All

One does not need to formally cycle an aquarium. And aquarium will cycle whether one does “cycling” or doesn’t do “cycling”.

2.3. How I Cycle

This is a very complicated method of cycling an aquarium which was invented by an obsessive compulsive chemistry nerd.

2.2. Many Ways to Cycle

There are literally thousands of ways to successfully cycle an aquarium. So things can be very confusing for any beginner in the hobby.

2.5. Aquarium Fish-in Cycling

This is a recommended method to cycle an aquarium which already has fish in it. This is a way to do it which keeps the fish 100% safe.

2.10. Nitrogen Cycle

This is a series of explanations of the aquarium nitrogen cycle. It starts out very simple and get more and more complex.