Common Aquarium Problems #1: New Tank Syndrome

April 18, 2024 Sarah Heximer

The problem

If you’ve just set up a tank within the last month or two, and your fish are sick or stressed, you may be experiencing new tank syndrome. An unfortunate but common occurrence, new tank syndrome is a problem where toxic compounds build up because of a lack of biofiltration. This is because a new aquarium needs time to allow beneficial bacteria to colonize the tank’s biofilter media, and establish the nitrogen cycle. If the tank is not cycled, there just aren’t enough bacteria to break down all the wastes produced by fish, and you end up with toxic levels of ammonia and nitrite.

Treatment & Prevention 

Below are some actions you can take to treat new tank syndrome:

  • Do weekly water changes of 25% or more until the tank is fully cycled and water quality stabilizes. These frequent water changes will help to dilute ammonia to keep fish safe during the cycling process.
  • Test your water quality every few days. You’ll know the tank is cycled when you see a peak and drop in ammonia and nitrite levels, followed by consistent testing under 1 ppm or 1 mg/L.
  • To speed up the cycling process, inoculate the tank by adding substrate or filter media from an established tank, or using a beneficial bacteria additive.
  • Avoid using ammonia neutralizers, as these products can deprive beneficial bacteria of the ammonia they feed on and slows the cycling process.
  • Avoid using untreated tap water to refill your tank or clean your filter media, as it can contain disinfectants like chlorine or chloramine, which can kill off the beneficial bacteria you’re trying so hard to establish.

With some time and attention, you can fix the water quality issues in your new aquarium and make it a place where your fish can thrive. Using MarinePure® Biofilter media gives the beneficial bacteria an ideal home where it can multiply.



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