SeaChem De-Nitrate removes nitrates, nitrites, ammonia, and organics from both freshwater and marine aquariums. The high porosity of De-Nitrate supports the proliferation of both aerobic and anaerobic bacteria that further remove these toxic aquarium byproducts. Removes nitrates, nitrites, ammonia and organics. Supports growth of beneficial bacteria that eliminate toxins. Suitable for fresh and saltwater tanks. Even when exhausted as an organic adsorbent, SeaChem De-Nitrate continues to be an excellent support for the biological filter and does not have to be removed. Directions: Place De-Nitrate to assure the flow of water through it, such as in a canister filter, chemical filtration module, or box filter. Flow rate should not exceed 200 L (50 gallons) per hour. If higher flow rates are unavoidable, use Matrix or Pond Matrix. It is best to rinse off dust before use. Once De-Nitrate has been used for several days, nitrate concentrations should start to fall and level off gradually at a concentration of 4-5 mg/L as nitrate. As long as nitrate concentrations remain under control, the product is not exhausted. Each 500 mL of De-Nitrate treats about 100-200 L (25-50 gallons), depending on initial nitrate concentration and the current biological load. Enough should be used to remove nitrate at a rate at least as fast as the rate of formation. If very high nitrates are initially present, they should be brought down to less than 20 mg/L with water changes.