The Xtreme BioFilter is a biological and mechanical filter. With the unique diffuser design, it provides powerful and throrough backwash and it takes less than 5 minutes once a month. The Xtreme Bio Media packing creates a dense packing which filters out dirt and debris down to 30 micron in particle size. The Xtreme Bio Media design gives a tremendous amount of surface areas for bacterial growth. With 870 square feet of surface area per cubic foot of the Xtreme Bio Media, it is considered as the highest value for biological filtration