How do I backwash my DE filter?
Vertical Grid: When the filter pressure rises 8-10 psi over the clean starting pressure, the filter must be backwashed. Turn off the pool pump. Rotate the multi-port valve to the backwash position or slide the slide valve up. When the pump is turned on, the dirty DE and water will flow out to waste. Once the water runs clear, turn off the pump. With a slide valve, push the handle down and start the pump. Once the pump is primed, add the required DE. If using a multi-port valve, rotate the handle to rinse. Turn on the pump and let water flow for 20-30 seconds, cleaning out the plumbing lines. Turn off the pump and rotate the valve back to filter. Turn on the pump and once primed add required DE.
When the pump is turned on, DE will recoat the tubes. The filter pressure will not drop to the original starting pressure, but will drop lower then the previous reading. (Example: the original starting pressure was 10 PSI. You “bumped” the handle when the pressure reached 20 PSI. After the bumping, the pressure dropped to 13 PSI.)
The pressure reading after bumping is the new starting pressure. When the pressure goes 8-10 PSI over this, the filter will need to be bumped again.
When there is no pressure drop after bumping or the pressure rises very quickly after bumping, the DE will need to be drained and replaced.
To replace DE turn off the pump, bump the handle to shake DE off of the tubes and open the drain valve. The pump can be turned on to help expel the dirty DE, but it should be for no longer than a minute. A jet-action cleaning wand can be Used to remove any remaining DE.
NOTE:Take a reading of this new clean starting pressure, so you have a reference point for the next backwash cycle. Water may need to be added to the pool to replace the backwashed water.