Fluval biomax ceramic rings have a complex pore system where beneficial bacteria can thrive with more capacity than most biological filter media biomax helps reduce ammonia and nitrite plus the rings allow ideal water movement throughout the media to ensure optimal contact time for efficient biological filtrationr r replace biomax every 3 monthsr r important replenish only half at one time to allow proper seeding from older media to newr r premium select media for use in fluval canister