Coralife BioCube Aquarium Replacement Filter Cartridges, 24 Count 24 individual replacement cartridges (12 packs of 2) Specially designed for use with all Coralife BioCube Aquariums This replacement cartridge is designed to fit CoraLife filters size: 14, 16, 29, and 32 Removes odors and discoloration from aquarium water and leaves it crystal clear Also appropriate for Oceanic BioCube aquariums and BioCube filters size: 8, 14, and 29