• THIS IS THREE OF THE THE 2-PACKS (6 Cartridges Total)

THIS IS THREE OF THE THE 2-PACKS (6 Cartridges Total) Replacement BioCube Filter Cartridge, 2-Pack, for all the Oceanic BioCube Aquariums and Coralife BioCube Aquariums. This is the Oceanic 8 BioCube Filter, Oceanic 14 BioCube Filter, Oceanic 29 BioCube Filter, Coralife 14 BioCube Filter & Coralife 29 BioCube Filter. Coralife recommends, for optimum efficiency, cartridges should be replaced every four to six weeks.