OASE BioStyle Biological Filter Foam Set of 2

2-in-1 Filtration – The BioStyle 30 ppi filter foam provides 2-in-1 filtration by catching debris/waste and promoting growth of beneficial bacteria.. Coarse Filter Foam – provides mechanical and biological filtration results in cleaner, healthier water for your aquarium inhabitants.. Contains two replacement foams – fit inside the chamber of the BioStyle Power Filter series. Quantity needed depends on the size of the filter.. Changing the filter foam – biological filter foams should be replaced after 12-18 months, depending upon aquarium size, number of fish and plants, and declines in filter performance.. Filter foams fit inside the filter frames (not included). Rinse foams with water before use.