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Understanding The Nitrogen Cycle In A Fish Tank Aquarium

When we talk about water parameters and optimum levels, this is all based around the nitrogen cycle which takes place in our fish tanks. The best way to explain this cycle is by means of an image.


As you can see from the above picture of the nitrogen cycle in a fish tank with fish and plants, the fish waste and decaying plants emit Ammonia (NH3) which turns in to Nitrite (NO2) through Nitrosomonas and eventually turns in to Nitrate (NO3) through Nitrospira. The plants will use up some of this Nitrate as well as the Ammonia however generally it must be removed regularly through performing water changes.

Technically it may be possible to never do water changes however the volume of water you would need in your aquarium compared to the number of plants and low number of fish might result in a fairly boring aquarium so water changes are always advisable to ensure the Nitrogen cycle is kept stable and no spikes are experienced.

API 800 Test Freshwater Aquarium Water Master Test Kit

API 800 Test Freshwater Aquarium Water Master Test Kit

  • Contains one (1) API Freshwater master kit 800, including 7 bottles of testing solutions, 1 colour card and 4 glass tubes with cap
  • Helps monitor water quality and prevent invisible water problems that can be harmful to fish and cause fish loss
  • Accurately monitors five most vital water parameters levels in freshwater aquariums: pH, High Range PH, Ammonia, Nitrite and Nitrate
  • Designed for use in freshwater aquariums only
  • Use for weekly monitoring and when water or fish problems appear

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