How to control nitrite in an aquarium?

When nitrite concentration is too high, you can directly add nitrifying bacteria culture, which is the key to breaking down nitrite. But aerate the tank when adding, so the bacteria do not consume too much oxygen and suffocate the fish.

Second, change part of the water, but not all at once to avoid stressing the fish – change only 1/3 every other day for a week. Finally, run the air pump and filter continuously for 24 hours to speed up circulation and return the water to a natural clean state.