How to Backwash a Pool Sand Filter

Step 1) Turn off the pool pump

Step 2) Set the filter valve handle to the ‘Backwash’ position and ensure the handle locks in place

Step 3) Turn the pump on and backwash for 3-5 minutes or until the water in the sight glass (located on the filter) is running clear

Step 4) Turn off the pump

Step 5) Set the filter valve handle to the ‘Rinse’ position and ensure the handle locks in place

Step 6) Turn on the pump and run the rinse process for 1 minute or until the water in the sight glass is clear

Step 7) Turn off the pump

Step 8) Reset the filter valve to ‘Filter’ and ensure the handle locks into place

Step 9) Turn on the pump

All sand filters use the same basic mechanics: when set to ‘Filter’, water flows from the pool, through the filter, and back into the pool. The sand inside the filter system blocks debris, dirt, and oil. A typical sand filter multiport system has 6 different settings – ‘Filter’, ‘Backwash’, ‘Rinse’, ‘Circulate’, ‘Closed’, and ‘Waste’.

However, when you vacuum your pool, a concentrated level of dirt and debris get deposited into the sand – the result being that the sand becomes dirty and clogged with contaminants that, if left unchecked, will reduce the sand’s ability to filter and, ultimately, end up back in your pool, reduce the clarity of the pool water. Backwashing prevents this. Backwashing reverses the flow of water, lifts up and flushes the sand, and then expels the dirty water via a waste line into the ground or drain.

In order to prevent residual blow back into the pool, once you’ve finished backwashing it’s highly advisable to rinse the filter. Just as the backwash lifts and flushes the sand, the rinse resets the sand to its original position for optimum filtration.

For more advice or assistance please contact us here: