AquaClear 20 Ammonia Remover Inserts are replacement filter media for the AquaClear 20 Power Filter. AquaClear 20 Ammonia Remover is ideal for new or heavily populated freshwater aquariums. It removes and controls harmful ammonia and nitrite, creating a healthy aquatic environment. Controlling ammonia levels is critical for reducing stress on fish. Exclusively designed for use in the AquaClear 20 Power Filter, Ammonia Remover is only suitable for freshwater aquariums. AquaClear creates a wide variety of products for freshwater tanks such as fish tank accessories, fish tank decorations, and aquarium filter media that is perfect for large and small fish tanks.