AquaClear AC70/110 Ammonia Remover Insert is ideal for new or heavily populated freshwater aquariums. It removes and controls harmful ammonia and nitrite to create a healthy aquatic environment. Controlling ammonia levels is also critical for reducing stress on fish. For the AquaClear AC70 Power Filter and AquaClear AC110 Power Filter. The Product Manual recommends you replace the Ammonia Remover Insert every month. 3-pack.