If you’ve ever changed your aquarium apparatus or just started a new tank only to find fish dying fast, you were probably dealing with new tank syndrome.

What is new tank syndrome?

New tank syndrome is a phenomenon where the biological filters responsible for converting fish waste of ammonia into nitrite and nitrate have not been established. It is common in new tanks but can also occur in an old aquarium that’s not fully cycled, causing an accumulation of ammonia to highly toxic levels that can kill fish.

The nitrogen cycle and new tank syndrome
The nitrogen cycle and new tank syndrome. Image credit: Aleron Val, Shutterstock.

What causes it?

After setting up a tank with clean water, it has less or no nitrifying (beneficial) bacteria. Beneficial bacteria are essential for converting ammonia into less dangerous forms, from nitrite to nitrate. 

Once you have set up a new tank, give it time before introducing all of your stock inside. Beneficial bacteria need enough time to grow, mature, and establish themselves properly inside the new tank.

It takes several weeks (4 to 12 weeks) for nitrifying bacteria to multiply and become sufficient in your tank.

As a result, the efficient working of the nitrogen cycle is enabled. The availability of beneficial bacteria in the tank is nature’s way of assisting with cycling.

Of course, the maintenance of safe gas levels depends on the nitrogen cycle, a robust water filter, and frequent water replacements.

Signs of new tank syndrome

New tanks can easily appear healthy until you introduce fish in them and things start going bad. As a beginner, you want to understand when your tank is healthy and when it is not.

Here are the signs and symptoms of new tank syndrome:

  • Cloudy water
  • Sudden death of fish
  • Smelly water
  • Fish gasping for air at the tank’s surface
  • Fish swimming at the surface of water for prolonged periods
  • Lack of appetite
  • Burned and reddened gills
  • Swimming abnormalities
  • Fish breathing fast
  • Lethargy

All these signs are occasioned by the accumulation of ammonia or toxic nitrite in the tank because it lacks biological filters.

Fixing new tank syndrome

There’s no quick way to transition your tank from being uncycled to being fully cycled unless you wait a few weeks for it to occur naturally. The best fix is to wait for the biological filters to establish to grow on their own.

Introduce 10-20% fish in the tank

You will need ammonia coming into the tank in order to establish a natural biological cycle as colonies of nitrobacter, nitrosomas, and other useful bacteria establish naturally. Therefore, introducing fish into the tank is key to fixing the new tank syndrome because as they feed, ammonia is released.

The problem is, you cannot stock your tank with many fish because you’ll simply kill them due to the ammonia overload. I recommend adding just 10-20% of the number of fish recommended for your tank size. These fish will introduce ammonia into the tank, which in turn starts the cycle of baterial action.

Expect to see spikes in the nitrite and nitrate levels as the bacterial colonies get established. This is perfectly normal.

Monitor the ammonia, nitrite and nitrate levels very closely to keep your tank healthy and avoid killing the fish.

Finally, slowly add more fish once the tank is fully cycled.

Perform a fishless cycle

A fishless cycle is the process of growing colonies of good bacteria into your tank’s filter before introducing any fish in the tank. It involves introducing ammonia directly into the tank to encourage the good bacteria to grow and cycle ammonia naturally.

You can do a fishless cycle for your tank to fix the new tank syndrome but you’ll have to time it exactly right for when your fish arrive into the tank.

A fishless cycle is essentially adding straight ammonia (and sometimes bacteria) into the aquarium and having it cycle without any fish in the system.

For example, organic waste such as unconsumed fish food begins to decompose in the aquarium, thus releasing ammonia that will jumpstart the fishless cycle.

How long does new tank syndrome last?

The tank is fully cycled when nitrites are being produced in the aquarium while nitrite and ammonia levels are zero. The nitrogen cycle and the new tank syndrome can last between 2 and 6 weeks.

Nitrifying bacteria grow slowly and the syndrome can last longer if tank temperatures are below 70°F.

Use test kits to check the water conditions or take the new tank’s water sample to your local fish store for tests to be performed.

Pro tip: Do not add more fish to the tank until it is fully cycled. More fish means increased ammonia levels in the tank, yet there are few colonies of beneficial bacteria to break it down.

When does new tank syndrome start?

The new tank syndrome starts immediately after setting up your tank and adding fish. The immediate addition of fish in the newly set up tank does not provide enough time for beneficial or filtering bacteria to grow and occupy the tank at sufficient levels.

Therefore, the use and breakdown of toxic gases into safe forms is limited or nonexistent. Without an adequate quantity of beneficial bacteria, ammonia and nitrite will become highly toxic and contaminate the tank, leading to the death of your fish.

How to avoid new tank syndrome

Any fish enthusiast can avoid the new tank syndrome or its harmful effects. Subsequently, below are a few things you must do.

1. Setup a new tank properly

Give the tank you have set up between 2 to 6 weeks to establish the good bacteria. The nitrogen cycle begins with the release of ammonia into the tank water. For that reason, there may be a need for you to have fish in the tank for the nitrogen cycle or nitrification process to start naturally.

Only add a few hardy fish species to your tank at the start. A hardy fish can survive in water with conditions that may not be safe and stable for most fish species.

Consult your local aquarium or pet store about the starter fish to buy. Once your tank has conditioned water, filter, and other tank requirements, and you have added hardy or starter fish, monitor the water parameters for the next two-six weeks.

2. Promote faster growth of beneficial bacteria

You can avoid the new tank syndrome by using a nitrifying kit or adding used gravel from an old tank. Gravel from a tank already in use has beneficial bacteria.

Transferring the gravel to a new tank also brings nitrifying bacteria. If there is no established tank, request used tank gravel from the store you are buying your starter fish.

Change the aquarium water every few days to reduce the toxic ammonia to a bare minimum. Replace about 20 percent of the water to speed up the occurrence and increase of beneficial bacteria.

3. Avoid overfeeding your fish

During the first few days of feeding your hardy fish in a new tank, do not supply large quantities of food. Food that remains uneaten becomes stale and rots to generate ammonia. By avoiding overfeeding, you can control the excess production of toxic gasses while allowing the growth of beneficial bacteria.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *