How to Backwash a Pool Filter

If you are new in the swimming pool world and wondering how to backwash a pool filter, you came to the right place. This article will provide you with a step-by-step guide on backwash a pool filter. Make sure to read the entire article from beginning to the end to understand the process to backwash a pool filter.

Process of backwashing a pool filter

The process is pretty simple and straightforward.

  • First, you need to switch off the pool’s pump.
  • Next, put the filter valve handle to the backwash position and make sure that the handle stays locked in place.
  • Now backwash for 2 minutes while the pump is on and do it as long as it takes the water to become much clearer. Now turn off the pump.
  • After that, you now have to put the filter valve handle to the rinse position and make sure the handle locks in place.
  • Now you will have to continue the rinse process for 1 minute while the pump is on. Further, you may have to continue the process until the sight glass is clear and it doesn’t have any water. Now turn off the pump.
  • In the next step, you will need to reset the filter valve to “Filter” and make sure that the handle locks into place. Turn on the pump now.

Usually, all types of sand filters available in the market use the same basic mechanism. When set to “Filter,” water flows from the pool via the filter and goes back into the pool. The sand in the filter works to block debris, oil, and dirt. A standard sand filter consists of 6 different settings, including filter, backwash, rinse, circulate, closed, and waste.

When the vacuum is performed, a certain amount of dirt gets into the sand. As a result, the sand becomes clogged with contaminants. If you don’t notice it, the filter’s ability is reduced and fails to maintain the charity of the pool water. Therefore, you need to perform backwashing to prevent this problem. Backwashing does reverse the flow of water, flush the sand, and also remove the dirty water via the waste line to the ground or drain. In addition to preventing residual blowback into the pool, after finishing backwashing once, you must rinse the filter.

How often should you backwash your pool sand filter?

A usual rule of thumb is once every 14 days. The right time to backwash is immediately after vacuuming your pool. You can also predict the backwashing time after checking the pressure gauge of the sand filter. When you see the KPA pressure on the gauge is north of 80 KPA, it’s the right time to backwash. Usually, normal operating pressures are between 50 and 75 KPA.

How can you reduce the need to backwash?

It is known to everyone that leaves, and other different types of debris can lead you to need to backwash your pool sand filter more often. In addition to reducing the need to backwash, you can invest some for using a good pool cover. Pool covers are low priced, ranging from $566-$1300. There are different types of pool covers available in the market.

Solar pool covers: one of the most preferred ones is solar swimming pool covers or bubble blankets. During the daytime, the blanket absorbs the sun’s warmth and preserves the warmth. Solar pool covers are the most cost-effective pool covers that can increase the water temperature up to 8 degrees by converting the pool into a solar heater.

Thermal Pool Covers: Thermal pool covers are also considered the popular form of pool covers. They not only help to fully block the sun’s rays that attack chemical levels but also retain the heat. Thermal blankets are usually made of thicker insulating foam material. Thus they cost a bit more ranging from $900-$3000 roughly.


If you have a pool and are worried about backwash a pool filter, the above guidelines will provide you the appropriate ways of doing it. You should also keep in mind that you also need to keep your pool free from debris, leaves, and other types of dirt. You should buy a pool cover to keep your pool free from all types of dirt.

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