Multi Media Filters are used with Pressure vessels with sand or other loose media and are widely used in industrial filtration applications. During the cleaning cycle, called “backwash”, the bed is lifted (or “fluidized”) to loosen the filter media and release trapped dirt which is removed in the backwash flow. After the backwash cycle, the bed is allowed to settle before the filter is returned to service (i.e., normal flow). A “Drain” cycle is used following the settling to assure the filtration media has sufficiently re-stratified and that any loose dirt is removed from the underdrain / collectors