This substance finds its uses in all parts of biology; from muscles to allow movement, the DNA blueprint for building cells, to the molecular machinery known as enzymes for carrying out the fundamental biological processes of life. The role of nitrogen in fishkeeping is equally significant, for it happens to be our friend when it comes to feeding our fish and keeping them healthy, but it can also be our enemy with respect to water quality.
The First Stage of Nitrification:
Ammonia (NH3) is a toxic gas composed of nitrogen and hydrogen produced by the decomposition of organic matter (fish waste, plants and uneaten food) in the first phase of the nitrification. With the support of nitrifying bacteria (namely, species of Nitrosomonas), harmful ammonia turns into less toxic nitrite.