With the cartridge style filter system the backwash procedure is not used. Instead you have to manually clean your filter grids using water and possibly a milt filter grid cleaning agent. The steps for cleaning a cartridge filter system are as follows: First turn pump off, open any air release valve on top of filter, open any drain valve on filter system allowing water to drain from filter tank. Open filter tank assembly after water has drained. Remove elements from filter tank and place in appropriate area for cleaning. Using a hose and nozzle spray filter elements off removing all debris. In some cases a mild cleaning agent must be used. If you must use a mild cleaning agent make sure you then rinse thoroughly to remove all filter cleaning agent from filter elements. Replace filter elements into filter tank, secure filter tank assembly, close any drain valves, turn filter back on. Allow filter to fill with water. When water escapes from air valve on top of filter, close air valve.