The primary reason most freshwater aquarium fish die is poor water quality.  The main causes of poor water quality are:

• Uncycled tank
• Insufficient filtration
• Insufficient water changes
• Insufficient removal of fish waste
• Too many fish for the size tank
• Contamination

Many people who are new to aquariums don’t understand how to identify water quality problems.  The three most important water parameters for freshwater aquariums are

• Level of ammonia
• Level of nitrite
• Level of nitrate

Ammonia, nitrite and nitrate are nitrogen-based compounds that are produced by fish in the form of waste, but also by decomposing food, etc.  The best way to test the levels of these compounds is by using a master test kit, found at most aquarium stores.

Non-zero levels of ammonia and nitrite are indications of New Tank Syndrome, also called a cycling tank.  See the New Tank Syndrome section below.

Elevated levels of nitrate (>40-60ppm) is caused by Old Tank Syndrome, discussed below.

Symptoms Of Water Quality Problems

The major problem with water quality problems is that fish don’t recognizably die directly from poor water quality.  They die from opportunistic diseases that take advantage of a weakened fish, such as:

• dropsy
• internal parasites
• bacterial infections
• fungal infections
• etc

New Tank Syndrome

“New Tank Syndrome” is the common name given when fish become ill or die in a newly establish aquarium.  Fish naturally produce ammonia as a waste product.  Excess fish food will rot and produce ammonia as well.  Aquariums containing fish need to establish a “cycle”, which is basically colonies of bacteria in the aquarium that process fish waste from poisonous ammonia and nitrite to less harmful nitrate.  Please see the page on cycling aquariums for more information.  In new tanks, tanks that have had the biological filter damaged or destroyed, or tanks that suddenly were overfed or had a big increase in fish, ammonia and nitrites will build up.  These compounds are quite poisonous to fish, and a build up of either or both ammonia and nitrite generally results in sick or dying fish.

If you suspect new tank syndrome, because the tank is new, a large amount of food was recently introduced, or many new fish were introduced, follow these steps:

1. Stop feeding the tank.  Continuing to feed will make the problem worse.  Most fish can easily go several days without eating.
2. Test the water parameters with a master test kit.  If none are available, take a sample of water to a local aquarium store, and they will generally test it for free.  This isn’t ideal, as many stores use unreliable “test strips”, but it should be accurate enough to show whether or not this is the problem.
3. Perform partial water changes until the ammonia and nitrite levels get to zero and stay there.  The aggressiveness of the changes really depends on the level of ammonia or nitrites.  The higher the level, the more frequent and large the water changes need to be.  At 1 to 2ppm, change 50% of the water daily.  Above that, change 60% to 70% twice daily.

Old Tank Syndrome

Old tank syndrome happens in cycled tanks with well functioning bio-filters.  Over time, ammonia and nitrite are consumed by bacteria to produce nitrates.  Nitrates are far less toxic to fish than ammonia and nitrite, but in high concentrations, it will sicken or kill fish.  Unless some action is taken to reduce the concentration of nitrates, eventually old tank syndrome will set in and result in dead fish.

Old tank syndrome can be avoided with these precautions:

1. Perform periodic water changes.  commonly 20% to 50% weekly, depending on the number of fish, amount fed, etc.  The target level for nitrates should be under 20ppm.  Using a master test kit and some experimentation will help you determine the right frequency and volume of water changes for your tank.
2. Don’t overfeed fish.  If you see excess food laying on the bottom of the tank after feeding, you are most likely feeding too much.
3. Vacuum the gravel periodically.  In tanks that have sand or gravel, over time fish waste and excess food get trapped and the decomposition process can become a serious problem for the level of nitrates.

If you suspect old tank syndrome, follow these steps:

1. As with above, stop feeding the tank.  Continuing to feed will make the problem worse.
2. Test the water parameters with a master test kit.  If none are available, take a sample of water to a local aquarium store, and they will generally test it for free.  This isn’t ideal, as many stores use unreliable “test strips”, but it should be accurate enough to show whether or not this is the problem.
3. Perform partial water changes until the nitrate levels get below 20ppm.  The aggressiveness of the changes really depends on the level of nitrates in the tank.  The higher the level, the more frequent and large the water changes need to be.

Treating Illness with Medication

Many fish-keepers will attempt to treat the apparent disease with antibiotic, anti-parasite or anti-bacterial medications, but not the underlying cause – water quality.  Indeed, particularly in the US where antibiotics are readily available, many new-comers make a bad situation much worse by treating a tank with medication that kills off the colony of beneficial bacteria, leaving the tank uncycled.

It has been my experience that, in nearly all cases, fish that are showing obvious signs of illness will not survive despite best efforts and intentions.  To be sure, there are many astute and experienced fish-keepers who can nurse a sick fish back to health, but such experienced people also know that prevention is far more effective than a cure.

Good Practices For Maintaining Fish Health

Filtration

Ensure the aquarium has the proper amount of filtration.   While there are a number of variables, such as volume of water, number and types of fish, amount of food used to consider, the general rule of thumb is to size the filter to pump the water between 5 and 10 times per hour.  For example, a 55G aquarium needs filters that will pump between 275 and 550 gallons per hour.  My strong recommendation is to purchase two smaller filters whose flow rate adds up to 10 times the volume of the tank.  The That might seem excessive, but it does ensure good filtration and provides some ability to ride out the failure of one filter.

Using a UV filter is also a very good way of eliminating opportunistic microorganisms in the aquarium.

Water Changes

As with sizing filters, there is are a lot of variables that go into how much and how often to perform water changes.  Internet forums are full of recommendations… from 20% per month to 20% per week.  There is a sizable contingent of well intentioned people who insist that anything more than 20% per week is harmful to the fish.  I do not subscribe to that way of thinking – fish will not suffer from having too much clean water.  I perform 50% changes weekly on my tanks with good results.  It’s a lot of work, but the Python makes it manageable.

Removal of Fish Waste

Some fish waste is dissolved or suspended in the water and is removed through water changes.  However, far more of it hangs around in the form of poop at the bottom of the tank.  Tanks that have gravel on the bottom make this situation hard to see, and without a thorough cleaning of that gravel, bad things can begin to happen, even if the other suggestions are followed.  First, I would strongly recommend most people to skip the gravel, unless there is a particular need.  Spend the money on pieces of drift wood or similar things to cover the bottom.  These can be moved around when it comes time to clean.  Regardless, the fish waste needs to be pulled out weekly as part of the water changes.  A gravel vacuum, like the Python, can clean both bare bottom and gravel bottom tanks.  Bare bottom tanks have a distinct advantage in that it’s easy to see the waste and see that it has all been sucked out.  In gravel tanks, a thorough cleaning of all the gravel is needed to ensure getting most of the waste.

Too Many Fish

Again, there is not a 100% reliable method of determining a safe number of fish for a tank.  The rule of thumb often quoted for freshwater fish is 1 inch of fish (at it’s adult size) per gallon of water.  This breaks down, however, with large fish like goldfish, oscars, etc.  Fish that are packed in to an over stocked tank are very likely to contract a serious infection and die due to the combination of a compromised immune system from stress.

Proper Tank Size

Determining the right size aquarium for the fish you are keeping is as much an art as it is a science.  Fish that grow large, such as goldfish, koi, knife fish, etc, will experience similar symptoms to those when a tank is stocked with too many fish.

Getting Immediate Help For Your Specific Problem

There are several great forums on the Internet that have emergency fish help sections where questions are generally answered in minutes by very knowledgeable, friendly and caring people.  Two such forums are here:

• FishForums.com Tropical Fish Emergencies – read this before posting
• AquariaCentral.com Freshwater Illness and Disease – read this before posting

If you are lost on how to proceed, or need validation on what you are doing, I strongly encourage you to post a message on one of those forums.  Be sure to read the link labeled “read this before posting” for which ever forum you visit.  Following that forums instructions on information to include in your post will make helping you much faster and easier.

Post from: Tropical Fish Central

Why Do My Fish Keep Dying?

The problems with a betta bowl

There are 3 main problems with bowls for bettas:

1. Bowls are generally quite small.  A betta, just like any other fish, should be kept in a larger volume of water than a bowl can provide to prevent the rapid build up of toxins and organic compounds from the fish and fish food.
2. Bowls are not heated.  Bettas are tropical fish.  They need the water to be between 76F and 82F, which is generally not achievable, at least steadily, without a heater.
3. Bowls are not filtered.  Filtering provides a mechanism for the nitrogen cycle to process ammonia and nitrite.  This is generally off set with frequent changes of the water in the bowl.

Why do stores sell bowls if they should not go in a bowl?

Simple: stores sell betta bowls because people buy them.  Unlike many other pets, there isn’t a big industry built up around preventing abuse and neglect for pet fish.  And the reality is, it keeps people coming back for more.  If you buy a bowl and a betta, the betta will live for some period of time – 6 months, maybe even a year or two.  After that, you’ll come back to buy another betta.  Additionally, selling bowls really expands their customer base.  Relatively speaking, there are not a lot of people who want a big aquarium in their house, but there are many more that find a decorative bowl acceptible.

Post from: Tropical Fish Central

Can a Betta Live in A Bowl?

A “cycled aquarium” is a tank that has established bacterial colonies to process fish waste, in the form of ammonia, into nitrates.  It is very important for aquariums with fish to be cycled, as ammonia is toxic to fish.  Adding fish to un-cycled aquariums will generally result in most or all of the fish dying.

What cycling is NOT

Despite the bad advice of so many pet store employees, cycling does NOT mean adding water to the aquariums and letting it sit and filter for a few days.  Doing that can be useful to make sure your equipment doesn’t die right away, but does nothing to cycle the tank.  Cycling a tank requires a source of ammonia for bacteria to consume.

How to Cycle a Tank

There are three methods for cycling:

• Fishless cycling
• Fish-in cycling
• Seeding a tank

EVERYONE who ever keeps fish has used one of those methods.  Those that are not aware of the choice have chosen fish-in cycling by default. 

Fishless

Fishless cycling requires adding a source of ammonia to the tank which will let the bacteria colonies build up to process the ammonia.  The most straight forward source of ammonia is from a bottle.  You’ll want to look for “clear ammonia” that does not have soaps or fragrance additives.

There are many, many resources available on the Internet to help with fishless cycling.

Fish-In

Fish-in cycling uses one or more fish as the source of ammonia.  For those who consciously perform fish-in cycling, a single fish is generally used.  Zebra Danios are probably the most common intentional cycling fish, because of their small size, hardy nature, cheap price and ready availability at most any pet store.

Everyone who starts an aquarium up, and adds fish immediately, or even after a week, is performing a “fish-in” cycle, whether they know it or not.  Fish-in cycles expose the fish to toxic levels of ammonia and nitrite which burn the fish’s gills and degrade it’s immune system and frequently result in the death of fish.  For this reason, sick fish in a new or cycling aquarium is known as “new tank syndrome”.

Seeding

Seeding a tank is basically transplanting bacteria from an established, cycled tank to an uncycled tank.  Commonly, gravel or filter pads from the established tank are suspended in the new tank.  A commercial product, called Bio Spira, is also avialable from some retailers.  Bio Spira is a pouch containing a pre-cultured bacteria colony ready to go.  It is important to note that Bio Spira has to remain cold until added to the tank, otherwise the colony of bacteria will die off due to lack of food.

Note that there are MANY products available for sale at stores that claim to cycle your tank, or “help the cycle”.  These don’t actually contain bacteria, meaning that you will still be cycling your tank when using them. (that includes the product called “Cycle”).

Recommendation

Fishless cycling is the generally preferred method for cycling tanks now.  Fish-in cycling is considered inhumane and inflicts damage to the gills of the fish and reduces the fish’s life expectancy.

Post from: Tropical Fish Central

Cycling a New Freshwater Tank

In this post, I’ll describe the most commonly required equipment and supplies for a standard freshwater aquarium.  This is a good list for keeping the most common types of community freshwater fish.  If you are keeping some species of fish, such as African cichlids, or you have extreme water conditions, such as very hard well water, you may require some additional equipment.

Basic Equipment Required for Starting an Aquarium

• Tank and stand
• Python no-spill for water changes
• Master test kit
• Clear ammonia for initial cycling of the aquarium
• Heater – not glass
• Thermometer
• Filter – canister filter, sponge filter or a “hang on the back” (HOB) kind
• Dechlorinator
• Fish net

Recommended Equipment for Starting an Aquarium

• Canister filter
• UV filter
• Master test kit
• Light

Optional Equipment for Starting an Aquarium

• Hood (may come with light, or may just be a flat piece of glass
• Algae brush
• Gravel
• Decorations
• Air pump/airstone (required if using a sponge filter)

Fish Medication

I don’t recommend beginners purchase any medications or salt.  Nearly all problems with fish fall into one of three categories:

1. Illness caused by poor water conditions
2. Illnesses that are extremely difficult to treat
3. Ich/Ick

Medication is not the best way to address any of these situations, and may well make the problem worse.

Salt

Too many people look for advice on how much salt to put in their freshwater tank.  Some specific fish, such as mollies, may benefit from salt, but in general salt is only needed for brackish or salt water fish.  The exception to this is in the treatment of ich/ick where aquarium salt is helpful during the treatment.  The proper salt is “Aquarium Salt” sold by pet stores.

Do not use:

• Epsom salt
• Marine salt (this is for salt water tanks)
• Table salt

Post from: Tropical Fish Central

Aquarium Equipment For An Fish Keeping Beginner

Large goldfish that barely fits into the small bowl

So, can a goldfish survive in a bowl?

The short answer is yes – for a while.   Many people equate the fact that a goldfish can live for some period of time in a bowl with their ability to live in a bowl in general.  The most common “comet” goldfish are generally cheap (under $0.25US) and sold while very small – usually less than 1 inch long and pet stores often have bowls in the vicinity of the gold fish.  All of this makes it reasonable to believe that they can be kept in a bowl.

No, they can’t.

There are two major problems with keeping goldfish in a bowl

1. There is no filtration in bowls, allowing ammonia and nitrite to build up – both of which are quite poisonous to fish
2. A bowl is not large enough for a goldfish to grow to it’s intended adult size of 6 to 8 inches.

The first problem can be mitigated with frequent water changes and light feeding.  The second problem can’t be solved in a bowl.

So, what can I expect if I keep a goldfish in a bowl?

In the best case, goldfish kept in a bowl that is regularly cleaned will live for several years, and will die from no apparent cause.  In the worst case, the fish will be weakened from ammonia and nitrite poisoning and will succumb to a bacterial and/or parasitic infection, usually visible as dropsy (where the scales stick out).

What is the best habitat for goldfish?

The best habitat is a large pond.

A more reasonable habitat for most goldfish keepers would be a tank holding over 20 gallons with a filter, for a single goldfish.  Add 10 gallons for each additional goldfish.

Don’t make the problem worse!

Too often, well intentioned “goldfish-in-a-bowl” keepers will see their goldfish displaying what is actually symptoms of infection or ammonia poisoning and interpret those symptoms as “loneliness”.  They will go out and purchase a second fish to go into the polluted bowl.  The combined fish now produce ammonia even faster.

Now that you know a single goldfish should not live in a bowl, you will certainly know not to add additional fish to a bowl.

Here are some videos that will show the size that goldfish will grow to if given the proper environment:

Post from: Tropical Fish Central

Can Goldfish Live In A Bowl?