Sobo Aquarium Sponge Filter comes With an airlift system, super biochemical sponge filter features silent operation, and has excellent filtering effect while oxyagenating and filtration of the water, The Soeciall developed foam materials supports the colonization of bacteria, allowing for mechanical filtration in addition to biological filtration, which will break down harmful waste, ammonia and nitrite material, resulting in a cleaner living environment for your fish, particular they are useful for as breeding filter or as secondary filter.