The filter sponge XF-380 is for the aquarium cleaning with a airlift system biochemical filter sponge features in silent operation and has a best power in filtration the sponge develops the foam material supports while oxygenating the water to allow the mechanical filtration in addition of the biological filtration, which will break the harmful waste, ammonia and nitrate material in a cleaner living enviroment for your fish the sponge filter is mostly used as the breeding filter or the secondary filters for the aquarium.