Hydor High Quality Professional Black Coarse Sponge Filter Pads for Filters Professional 150Hydor Professional Canister Small Black Coarse Filter Pads are designed to be in the first stages of the canister filtration sequence in order to remove the larger pieces of debris and organic matter from aquarium water before going through other stages of filtration. Offers maximum performance and high filtration to remove debris, dirt and bacteria from fresh water and salt water aquariums Simplify the process of obtaining crystal clear water This