Oase BioStyle Disposable Cartridge Set 4PK

All BioStyle models come with multi-stage filter cartridges and biological filter foams. Multi-stage Filter Cartridge Comes standard in all BioStyle models. Disposable cartridge houses 3-stage filtration. 45 ppi Filter Foam: Traps debris and waste and also offers surface area for beneficial bacteria. Three chemical media mix: Carbon, zeolite and phosphate binder. Removes odors, impurities, and harmful nutrients from the water. Filter fleece: Traps extremely fine debris for a water polishing effect. The filter cartridge should be replaced after 4-6 weeks, depending upon aquarium size, number of fish and plants, and declines in filter performance. Replacement cartridges are available in a 2-pack and a 4-pack.