The biofilter, or bacterial filter, removes harmful ammonia from the fish tanks. The filter is the key component in maintaining water quality. In a RAS system the mechanical filter is used to remove the suspended solids from the system water flow. These solids, primarily faecal matter, need to be removed in order to maintain water quality. There are multiple types of mechanical filters, including drumfilter and sedimentation filter. Sedimentation filter The water flowing from the fish tank(s) is