How to Backwash a Sand Filter

Backwashing your sand filter is a simple process that cleans the sand inside your filter using clean water from your swimming pool.

By turning your filter’s multiport valve to “backwash,” and powering up the pump, the pool water is reversed through the sand and pumped directly out of your “waste/backwash” valve.

If you don’t want to read, you can watch our video on backwashing a sand filter.

VIDEO: How To Backwash A Sand Filter

To backwash your swimming pool sand filter, all you need to do is to follow a simple set of directions.

  1. Attach a long pool hose or backwash collapse-able host to the waste or backwash port on your multiport valve on you sand filter
  2. Turn your filter system off and switch the multiport valve handle to “Backwash” position
  3. Turn your filter back on and let the water rush out of the backwash port and through the backwash hose for about a minute or until the water starts to run clear
  4. When it is finished turn your pool filter system off and turn the handle to the rinse position.
  5. Turn your filter back on and rinse your filter for about 30 seconds.
  6. Turn your pool filter system off again and return the multiport valve to the original filter setting and your finished.

Note: Never turn the multiport valve handle while the pool filter is on and running. This could cause the rubber diverter gasket inside your multiport valve to come loose or break which will in turn cause water to leak out of the wrong ports while it’s running.

Additional Note: You should only backwash your filter when your pressure reaches about 10 pounds (psi) over the normal running pressure. Remember that the more debris and so called junk in your filter will help to catch finer debris and junk.

Happy Swimming!

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