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What is ‘new tank syndrome’?

‘New tank syndrome’ is commonly experienced in the first weeks of a new aquarium and is caused by an immature filter and excess waste.

‘New Tank Syndrome’ is a term used to describe problems that occur due to the build-up of invisible, toxic compounds in an aquarium. It gets its name as the issue is most likely to occur when your filter is maturing when starting a new aquarium. The full population of friendly bacteria can take up to 2 months to establish in your filter to a level where they are able to process all the waste being produced by your fish.

New Tank Syndrome is extremely common and can be a very frustrating and upsetting start to fish keeping as it often results in the death of your lovely fish. However, understanding its causes can help you to minimise or avoid problems completely.

Understanding the role of your filter, particularly the biology of the  bacteria-driven Nitrogen Cycle, before you start your aquarium is the best way of preventing new tank syndrome.

The Nitrogen Cycle is a natural biological process that occurs in your filter and helps to maintain a healthy environment for your fish. The video below explains more…

However, this Nitrogen cycle process takes a while to establish in a new filter.

Our top tips for avoiding New Tank Syndrome:

  • Adding a product like Fast Filter Start when you introduce fish will help your filter bacteria mature faster.
  • Introduce fish gradually, starting with a few strong species.  Once the filter is mature (there is no Ammonia or Nitrite) add a few fish at a time until you reach the advised maximum stocking level for your aquarium, this allows the friendly bacteria to grow to match the waste being produced by the fish.
  • Feed sparingly in the first few weeks, once or twice a day, removing any uneaten food after 5 minutes. More fish die of over feeding (uneaten food left to rot) than underfeeding.
  • Monitor your water quality! Many water problems are invisible so don’t just sit back assuming everything is ok in there. Test the quality and make a note of the results.
  • Carry out regular water changes – 20% once a week in new aquariums- this dilutes toxic waste compounds (ammonia and nitrite) to help whilst the filter matures. Later you will be able reduce water change frequency to 25%, once a month.

Just remember that patience and vigilance are key. Don’t rush, enjoy your aquarium!

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