JBL NitratEX Although nitrate (NO3) is non-toxic, it stunts the growth of fish and plants and leads to the excessive growth of algae in aquariums and ponds. Nitrate is only broken down by bacteria under anaerobic (oxygen-free) conditions. These occur, for example, in the floor covering material or in the reef rock of saltwater aquariums. Every filter which operates on normal biological principles produces nitrate. The nitrate consumption of plants is often not high enough, and nitrate becomes enriched in the water, leading to an increase in algae growth.JBL NitratEX reduces unacceptably high nitrate levels trough ion exchange. 250 ml JBL NitratEX absorb up to 9000 mg nitrate within a few hours. That approximately corresponds to a 200 l aquarium (minus decoration etc. approx. 180 l) with 50 mg nitrate/l. When the capacity has been exhausted, none of the nitrate is released back into the water. Simply regenerate JBL NitratEX with salt without iodine and it is ready to be used once again.