To backwash a pool filter, turn off the pump, set the multiport valve to BACKWASH, turn the pump back on for 2-3 minutes until water runs clear, then switch to RINSE for 30 seconds before returning to FILTER mode.
Changing pool filter sand involves shutting off equipment, removing the multiport valve, carefully extracting old sand, and adding new #20 silica sand in layers while avoiding damage to laterals.
Turn off your pump, switch the multiport valve to 'Backwash', run for 2-3 minutes until water clears, then switch to 'Rinse' for 30 seconds before returning to 'Filter' and adding fresh DE powder.
