Foam AquaClear filter inserts are specifically developed for use with AquaClear Power Filters . They will effectively remove waste and floating debris from your aquarium water. The numerous attachment nodes in the foam also allow for the establishment of thriving colonies of nitrifying bacteria to aid the biological balance of the biosphere and encourage biological aquarium filtration. This AquaClear foam filter insert may be used for freshwater or marine aquarium filtration. Designed for use with the AquaClear 20 model power filter. For a complete list of replacement parts and media, please see AquaClear Power Filter Replacement Parts and Media . For more information on mechanical and biological filtration, please read our article on Aquarium Filter Maintenance .