Nitrite is a harmful chemical substance in seawater, which is caused by the decay of residual bait and fish excrement. The content of nitrite in seawater should be controlled below 0.3 milligrams per liter. If the content of nitrite exceeds 0.5 milligrams per liter, the lives of marine fish and other invertebrates in the aquarium will be threatened. Nitrite in seawater can be effectively removed through a biological filtration system. Denitrifying bacteria and nitrifying bacteria in seawater convert nitrite into harmless nitrate. The content of nitrate in the aquarium should be controlled below 5 milligrams per liter.

In addition to nitrite, the content of silicon in seawater should also be lower than 5 milligrams per liter. The higher the content of silicon, the more vigorous the growth of brown algae in seawater. Quartz sand is mainly composed of silicon dioxide, so it is preferable not to use quartz sand with high silicon content as the substrate in the aquarium. In order to control the growth of brown algae, the content of silicate must be controlled. The content of silicate, iron, nitrite, and other substances in seawater can be measured using professional chemical solutions.

About nitrite in tropical marine fish tanks.