By | September 2, 2017
Reading Time: 3 minutes

How to Backwash Sand Filter

Backwash sand filter? It is the most important part of your pools health. No other part of the pool system removes fine debris from the water.

How a sand filter works

Your sand filter cleans debris out of your pool water. It collects the debris in the sand chamber. The water enters the sand filter chamber at the top of the sand filter and as it moves down thru the sand the debris is trapped between the sand.  This trapped debris adds resistance/pressure to the overall flow of water thru the filter. Backwashing runs the water through your sand filter from the bottom of the sand filter up thru the sand.

sand filter water movement path filtering

This motion pushes the accumulated debris on the top of the sand and the trapped debris in the sand out of the sand chamber.  This allows the collected debris to exit the filter to waste. This is accomplished by setting the valve to the “Backwash” position. Backwashing should be done every few weeks during the swimming season.

sand filter water movement path backwash

When to backwash

There is a pressure gauge on your sand filter. It will help indicate when it is time to backwash your filter. As the sand filter collects debris, the pressure gauge shows an increase in pressure change. When the pressure reaches 8-10 psi above your clean filter starting pressure you will want to backwash your filter.

A note on the multiport valve operation. This valve is how you divert the water stream thru the sand filter or even if you want to completely bypass the filter. This valve has a spider gasket seal that prevents the water from moving in the wrong direction. This valve’s seal/gasket life can be shortened considerably if you keep changing direction whenever you turn the selector handle. Always turn the valve handle in the same direction to ensure a longer seal/gasket life.

If your filter did not come with one, you will need a backwash hose as well as a clamp to attach the hose to your filter. You can also add a clear backwash sight glass section in the plumbing to waste to help determine when the water is running clean. If you choose not to add a clear section to the waste plumbing you will need to watch the backwash hose end for clear water when backwashing.

Related Article: Deep Cleaning a Sand Filter

How to Backwash Your Sand Filter

  1. Turn your filter’s pump off.
  2. Make sure that your backwash hose is properly attached and rolled out, with no kinks or bends.
  3. Turn your valve clockwise to the “Backwash” setting.
  4. Turn pump back on to start the Backwash cycle. This process can take several minutes depending on your filter and the amount of debris in your filter. If your filter has a sight glass, use it to visually gauge the backwashing. Debris will appear in the glass along with the water. When the water turns clear with little to no debris showing, turn the pump off again.
  5. After the Backwash cycle, the sand in your filter is disturbed from the water moving thru it in reverse. The sand also has debris in the cleanest part of the sand(bottom of the sand filter). This dirt must be forced out of this area or it will go back into your clean pool.  So the next step removes this dirt/debris to waste and sets up the sand for the next filtering cycle.
  6. Set your filter’s valve to the Rinse cycle.
  7. Turn the pool pump on. The Rinse cycle resettles the sand and delivers any debris toward the bottom of the sand chamber to waste and not your pool. Let this run until the water runs clear once more, then turn your pump off.
  8. Your filter’s sand is now ready for another filtering cycle. Set your filter’s valve to the Filter position.
  9. Restart your pump.


(Mybusyretiredlife.com All Rights Reserved)

(Mybusyretiredlife.com All Rights Reserved)

(Mybusyretiredlife.com All Rights Reserved)

RayC.
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