Sand Filter: To clean a sand filter, use a sand filter cleaning solution. This solution can be poured into your pump basket when it is turned off. The valve on the front of the pump must be closed before you can start the pump again, for about 10 seconds. Then, you can open the lid of the pump basket, and dilute the remnants of the solution with water.
This process will pump the solution into the filter, where it should sit overnight to cleanse the sane. After 12 hours, turn on the pump with the filter handle in the backwash position for 2 minutes, then switch the handle to rinse for 1 minute.
Always remember to turn the pump off in between filter handle position changes.
Cartridge Filter: Remove the filter cartridges, and soak in a cleaning solution. Hose or off the filters, using low pressure so that the filter pleats do not tear. The goal is to clean between the pleats of the cartridge filter paper elements.
Before you clean either type of filter, ensure that you shut off the heater and pump, drain the water, and close all valves before removing the filter head.