SeaChem De-Nitrate removes nitrates, nitrites, ammonia, and organics from both fresh and marine water. The high porosity of De-Nitrate supports the proliferation of both aerobic and anaerobic bacteria that further remove these toxic aquarium byproducts. Flow rate should not exceed 50 gallons per hour!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.