AquaClear Ammonia Remover Filter Inserts are natural ammonia removing filter media. Ammonia Remover is effective in freshwater aquariums for the control and removal of ammonia. Removes and controls harmful ammonia Ideal for new to heavily populated aquariums Alternate chemical stage The use of AquaClear Ammonia Remover is strongly recommended on a consistent basis for the control of potential ammonia surges andor when biological conversion of toxic ammonia is compromised or impossible. For freshwater use only. Choose the size that fits your AquaClear filter. Specifications 20 Gallon 5 20 gallon aquariums 30 Gallon 10 30 gallon aquariums 50 Gallon 20 50 gallon aquariums 70 Gallon 40 70 gallon aquariums 110 Gallon 60 110 gallon aquariums