Nitrifying bacteria and denitrifying bacteria are not used together. Nitrifying bacteria are generally cultured during fish farming. Its function is to convert ammonia nitrogen in water into nitrate, so as to avoid fish being poisoned, and nitrate can also become nutrients of aquatic plants. Denitrifying bacteria, on the other hand, convert nitrate into ammonia nitrogen, which is not helpful for fish farming. In addition, nitrifying bacteria like aerobic environment, while denitrifying bacteria need to survive in anaerobic environment.

1. Prepare container: To establish nitrification system, nitrifying bacteria should be given a shelter first. The best containers are bacteria houses, and ceramic rings can also be used. They can provide a shelter for nitrifying bacteria, so that bacteria can adhere to them, thus avoiding floating in water and exerting their functions better.

2. Pour raw materials: In order to speed up the establishment of nitrification system, it is necessary to pour a proper amount of raw materials, that is, nitrifying bacteria culture solution, into the fish tank. Generally, when the bacteria are cultivated for the first time, they should be added once a week. After one month of continuous addition, they can be unnecessary, and the nitrification system is basically established.

3. Turn off the lights and explode oxygen: As aerobic bacteria, the growth of nitrifying bacteria can not be separated from sufficient oxygen, so it is best to turn off the lights and explode oxygen during bacteria culture, which can shorten the culture period and help maintain water quality.