The Weald Aquatics Blog - Ammonia and Nitrite in freshwater aquariums - another blog post from Weald Aquatics | Aquarium & Pond Fish Shop in Kent


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Ammonia and Nitrite in freshwater aquariums

Blog post written by Andy | 04 June 2013 | Category: Aquarium maintenance

Last month in our blog we wrote about nitrates in aquarium water. In this blog we will look at ammonia and nitrite which are eventually broken down into nitrates.

Ammonia is excreted by fish which is immediately broken down into nitrite in a matured aquarium by the bacteria in the filter system. The nitrite is then broken down into nitrates by different bacteria in the filter system.

Both ammonia and nitrite are toxic to fish even in small concentrations, so it is to best avoid having both in the aquarium.

When starting a new aquarium, levels of bacteria in the filter system will be zero and therefore unable to break down both ammonia and nitrite. In order to keep both these levels as low as possible, new fish should be added slowly along with treatments to boost the filter bacteria such as Bacterlife or API Stress Zyme.

With a matured filter system, both ammonia and nitrite will be kept at acceptable levels. However these levels will rise if the bacteria in the filter are killed by either washing all the filter media in tap water or the filter system pump stops working for a number of hours.

In the event of losing all the bacteria in the filter system, you will need to change at least 30% of the water and add a double dose of either Bacterlife or API Stress Zyme every two days for about a week until the bacteria returns to the correct levels. Also feeding the fish every two days will to help the bacteria levels return to normal concentrations.

Monitoring ammonia and nitrite concentrations is the most effective way to check that the aquarium water parameters are at ideal levels. This can be achieved using dedicated liquid ammonia and nitrite test kits. Keeping ammonia levels at 0.3mg/litre or lower and nitrite levels lower than 1mg/l will not only keep the fish in excellent condition but will also not cause any undue stress in newly introduced fish.


API Stress Zyme
Bacterlife and API Stress Zyme will help to keep bacteria at the correct levels in your filter.