how to backwash your pool filter

How Do I Backwash My Pool Filter? 4 Simple Steps

In Arizona Swimming Pool Blog by Les Greenfield, Owner / Operator

Backwashing your filter in 4 easy steps:

Step 1. Set the pump to backwash

To get started you’ll need to turn off your pool pump, and check the filter basket for larger debris, such as leaves or branches. Clear out the filter basket, and then turn the handle of the pump to “backwash.”

Step 2. Watch the filter

Next, turn the power on the pump. The entire backwash process should take 3 to 5 minutes. As you watch the water moving in the pool filter, observe the amount of particles swirling around. The backwash process is usually done when the water appears to be clear.


Step 3. Rinse the filter

Turn the power off on the pump and move the handle to the “rinse” position. Turn the pump back on and let the filter rinse for about one minute. This step is important for clearing out any remaining particles from the filter, and also allows the porous filtering material – silica sand or diatomaceous earth – to settle back. When completed, turn off the pump.

Step 4. Filter the water

Now that you are done backwashing your filter, you’ll move the pump handle back to “filter” and turn the pump back on. Allow the water to fill in the pool before adding the necessary chemicals.


Why do I need to backwash my pool filter?

Backwashing your pool filter is an important part of pool maintenance. Proper filtration of a pool maintains cleanliness by removing debris from plants and another matter that land in the pool, as well as eliminating such microorganisms such as Cryptosporidium and giardia, which tend to congregate in standing water, thus preventing water borne illnesses. Your pool filter contains a porous material such as silica sand or diatomaceous earth, which captures larger organic material as clean water passes through and returns to the pool. Over time, as more material collects in the filter, it becomes difficult for water to pass through. When you backwash your pool filter, you are essentially reversing the flow of water through the filter to remove the collected waste, which then travels through a hose for disposal.

How often should I backwash my filter?

If your pool is used regularly and stands near plants that shed such as trees or bushes, it is recommended that you backwash your filter once a week. When the filter is logged with a lot of debris and organic matter, pressure may build up in the filter tank, which may not be safe. If you do not have a weekly maintenance schedule for your pool, check the gauge on the tank; it is recommended to backwash the filter when the pressure gauge reads between 8-10 pounds per square inch (psi).

Final notes

Backwashing the pool filter will remove a small amount of water from your pool. Be sure to complete the entire backwashing process before adding more water and any necessary chemicals. Though the entire process should take no more than 10 minutes, it is an important part of maintaining a clean pool.