The perfect hanging filter for aquascaping aquariums. The triple action filter consists of two cassettes: the first is filled with crystalmax, a very porous biological media in fritated glass. This acts as a sponge for microorganisms, it breaks down waste and other harmful substances quickly and effectively. The second cassette is filled with filter foam with a 100% open structure for optimal filtration, and active charcoal which eliminates organic waste, chemicals and water colors.