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New Tank Syndrome

Why Are My Fish Dying in My New Aquarium?

(The First Tank Guide)

What Is 'New Tank Syndrome?'

New tank syndrome is a generic and all-encompasing explanation for loss of fish in an aquarium that is under two months old.

There are really a wide number of things that these losses could be more accurately attributed to, but the fact that many new fish tank owners encounter these problems has resulted in getting them all lumped together.

So What Really Causes 'New Tank syndrome?'

Though the actual cause of death can range from poisoning to disease, or from improper water conditions to stocking problems, the root of all these is twofold.

  1. Elevated ammonia levels due to an ineffective biological filter.
  2. Poor care due to an inexperienced owner or care-giver.

When you first set up your aquarium, the biological filter is not ready to handle the waste the fish are producing. Getting the biological filter up-to-speed requires putting the tank through a process called cycling the aquarium. This allows naturally occurring and ubiquitous bacteria to populate the filter media in the aquarium's filter and begin processing the ammonia produced by the fish into (eventually) relatively harmless nitrate which you can then remove with your regular, weekly 10-15% water changes.

Until the biological filter can process the fish's waste, the fish are swimming in it. This is stressful to the fish.

Directly, the elevated ammonia in the water reduces the availability of oxygen, making it harder for the fish to breathe. It also can cause a variety of other health problems directly, not the least of which is blindness. For these reasons, it is important to keep up with extra water changes while the tank is still cycling.

Indirectly, the elevated waste levels in the fish tank stresses the fish, making them more susceptible to disease and making any harassment they get from other fish or any other stressers they have to deal with that much worse. For these reasons it is also important to keep up with the necessary extra water changes during the cycling period.

In addition to the ammonia poisoning issues, the fact that a new aquarium owner does not have experience caring for a fish tank and the fish in it also contributes to this stress and loss.

New aquarium owners are more likely to make simple mistakes, such as over feeding the fish, which will contribute to poor water quality, increasing the waste related problems explained above, or having the temperature wrong, which increases the general stress the fish are under.

What Can I Do to Avoid 'New Tank Syndrome?'

  1. Understand the cycling process.
  2. Keep the population in your tank low until the tank has cycled.
  3. Keep up with the extra water changes necessary during the cycling process.
  4. Do some research on the care requirements of the fish you are interested in keeping before purchasing the fish.
  5. Be careful with your tank maintenance.
  6. Watch your feeding, make sure the fish eat everything offered in under two minutes.

These simple tips should help you avoid unnecessary losses to 'new tank syndrome' while your new aquarium is cycling.

Can't I Just Add Something to the Tank to Avoid 'New Tank Syndrome' altogether?

Simply put, no, you can't. There are people that will try to sell you ammonia removers which will remove the ammonia, but make the cycling process more difficult. Others will try to sell you bacteria boosters to make the tank magically cycle overnight, but these are highly unreliable.

Your best bet is to carefully cycle the tank with a small number of hearty fish, and keep up with the necessary extra water changes while you do so.

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July 2, 2012
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April 12, 2004
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