Bead filters rely on the use of a media that provides a high surface area/volume ratio. This allows for support of the necessary amount of biomass, in the form of a biofilm, to properly remove organic and inorganic waste from the water, making it suitable for fish and other normal aquatic life. Within the biofilm it is possible to carry out aerobic, facultative anaerobic, anaerobic and chemosynthetic processes if all the necessary bacterial species are present.