Accordingly, the aquatic environment is not able to clean itself under these circumstances, and limits have been reached in many places as to water changes and the benefits of more chemical additives. Mortality and poor or abnormal growth are symptoms of a bad aquatic environment. If the aquatic environment is improved, the symptoms will disappear because the cause has been eliminated. This on the job training has been done to the extent that these biologically active seed cultures are strains which are 1000 times more active than those found in nature. By adding on a regular basis, these more efficient cultures establish themselves and maintain dominance over those less efficient already present.
Nitrification is a two-step process than involves two groups of microorganisms.
The first step is oxidation of ammonia to nitrite. Nitrosomonas is the most common genus involved in this reaction. The most common genus involved in the second stage, oxidation of nitrite to nitrate, is Nitrobacter . They are very fastidious in growth habits and attempts to culture them commercially have met with little success. In addition, ammonia may be oxidized directly to nitrogen gas.