HOW TO BACKWASH A SAND FILTER

 
 
 
 

Sand filters are relatively easy to maintain. Let's take a look at WHY, WHEN, and HOW to backwash a sand filter with a multipart valve.

WHY

The sand used in a pool sand filter is specially graded to trap particles in the 20-100 micron range. With time, contaminants like dirt, debris, and oils will start to clog the sand to the point where the water flow greatly decreases. To be able to clean the sand, the filter needs to be backwashed. Backwashing reverses the flow of water to the filter, lifts and flushes the sand, and then sends the dirty water out via the backwash / waste line.

WHEN

Look out for these top two signs it's time to backwash:

  1. INCREASE IN PSI - PSI (pounds per square inch) is the measure of pressure that your filter is operating on. You'll know it's time to backwash when the filter's pressure gauge rises 8-10 psi over its normal baseline.

  2. DECREASE IN WATER CLARITY - If you notice your pool water is a little cloudy or see debris floating that the filter doesn't seem to be capturing, it could mean the filter isn't working as well as it should. 

HOW

  1. Turn the pool pump OFF

  2. Turn the multiport valve to the BACKWASH position, making sure that the handle is locked in place.

  3. Hook up your backwash / waste hose and place it where you want to dump the wastewater.

  4. Turn the pool pump ON and run the pump for at least two minutes. The water in the sight glass will change from cloudy to clear.

  5. Turn the pool pump OFF

  6. Turn the multiport valve to the RINSE setting, making sure that the handle is locked in place. The RINSE setting will reset the sand and flush out any remaining dirty water to WASTE.

  7.  Turn the pool pump ON and run the pump for 15-30 seconds.

  8. Turn the pool pump OFF

  9. Turn the multiport valve back to the FILTER position, making sure that the handle is locked in place.

  10. Turn the pool pump ON for normal filter operation.

  11. Check the filter pressure gauge and confirm that the pressure has dropped back to your normal baseline.

/ HAPPY SWIMMING /

If you have any questions about backwashing your sand filter, let us know, we have experts on hand to answer all your questions!

 
Pool MaintenanceElizabeth Johnson