Keep aquarium water clean, clear and free from toxins with this Activated Filter Carbon filtration media from API. It works to remove colors, odors and poisonous waste from both fresh and saltwater aquariums. Organic materials like fish waste, algae and uneaten food lower water quality and can cause stress, illness and ultimately harm your fish. This media uses a special blend of highly activated carbon to help absorb dissolved contaminants including chloramines, chlorine, tannins and phenols. Best of all, it can be used in all filter cartridges.