API Super Activated Carbon Aquarium Canister Filter Contains one (1) API SUPER ACTIVATED CARBON Aquarium Canister Filter Filtration Pouch 1-Count Clears aquarium water removing aquarium pollutants, including colors, odors, and toxic compounds which cloud water and degrade water quality. Contains high-porosity filtration media for superior cleaning power. Easy-to-use pre-dosed pouch fits most canister filters on the market, for use in freshwater, saltwater and reef aquariums Use when starting or maintaining an aquarium, replace monthly or sooner if aquarium is heavily stock and/or colors and odors are detected