AquaClear Activated Carbon Filter Insert 3pk Ultra grade carbon inserts that will improve the water color, clarity and odor in your aquarium; without changing the characteristics of your water. Smoke, chlorine and aerosol spray contaminants are easily and safely removed. Impurities are absorbed, while a broad spectrum organic compound remover makes it one of the best absorbing products you can buy. Teh chemical filtration stage for AquaClear filters. For use in both fresh and salt water aquariums. Features: Premium, research grade carbon Absorbs odors, discoloration and impurities Improves water clarity Item Specifications: Contains 3 inserts 20 gallon for AquaClear Mini filter 30 gallon for AquaClear 30 filter 50 gallon for AquaClear 50 filter 70 gallon for AquaClear 70 filter