how do i backwash a pool filter


Author: Poolking - Swimming Pool Equipment Manufacturer

How to Backwash a Pool Filter: A Complete Guide

1. Introduction to Backwashing a Pool Filter

2. Why is Backwashing Important?

3. When to Backwash a Pool Filter

4. The Backwashing Process

5. Troubleshooting Common Backwashing Issues

Introduction to Backwashing a Pool Filter

Backwashing is an essential part of pool maintenance. It involves reversing the flow of water through the filter to remove debris and other impurities that have been trapped inside. Backwashing is typically done on a regular basis, usually once a week or more often if the pool is heavily used. This article will provide a step-by-step guide to backwashing your pool filter, including when and why it is important.

Why is Backwashing Important?

The primary reason for backwashing is to remove debris and other particles that have collected in the filter over time. When the filter is clogged with debris, it cannot effectively remove contaminants from the water. This can lead to cloudy water, algae growth, and other problems.

Backwashing the filter helps to ensure that the water is clear and clean. It also helps to extend the life of the filter by preventing damage from clogging.

When to Backwash a Pool Filter

The frequency of backwashing will depend on a number of factors, including the size of the pool, the amount of usage, and the type of filter being used. As a general rule, it is recommended that you backwash your filter once a week during the pool season.

You may need to backwash more often if the pool is heavily used, or if you notice that the water is becoming cloudy or discolored. It is also important to backwash after a heavy rainstorm or other significant event that may have introduced debris into the pool.

The Backwashing Process

Before you begin the backwashing process, you will need to locate your pool filter and turn off the pump. You should also turn the valve to the "backwash" position.

Step 1: Turn off the Pump

To begin the backwashing process, turn off the pool pump. This will help to ensure that water does not flow through the filter during the process.

Step 2: Turn the Valve to the "Backwash" Position

Next, turn the valve to the "backwash" position. This will reverse the flow of water through the filter.

Step 3: Turn on the Pump

Once the valve has been set to the "backwash" position, turn on the pump. Water will begin to flow out of the backwash hose and the waste pipe.

Step 4: Wait for the Water to Run Clear

Allow the water to run through the filter for several minutes, or until the water flowing out of the backwash hose runs clear. This indicates that the debris and other contaminants have been removed from the filter.

Step 5: Turn off the Pump

Once the water is running clear, turn off the pump and switch the valve back to the "filter" position.

Step 6: Rinse the Filter

If your filter has a "rinse" setting, engage it for several seconds to flush the filter and settle the sand before using the "filter" setting again. If not, keep the valve in the "backwash" position and run the pump for just a few more seconds to even out the sand, then switch the valve back to "filter".

Troubleshooting Common Backwashing Issues

Sometimes, problems can arise during the backwashing process. Perhaps the water pressure in the pool is low, or the backwash hose is clogged. It is important to troubleshoot these issues to ensure that the backwashing process is effective.

If you encounter low water pressure, the first thing to check is the backwash hose. Ensure that it is not clogged or damaged, and if so, replace it before attempting to backwash the filter.

If the water pressure is still low after replacing the hose, there may be a problem with the pool pump. It may be necessary to call a professional to repair or replace the pump.

In addition, if the water continues to be cloudy or discolored after backwashing, you may need to replace the filter media or adjust the chemical levels in the pool.


Backwashing is an important part of pool maintenance that should not be neglected. It helps to ensure that the pool is clean and clear, and extends the life of the filter. By following the steps outlined in this article, you can successfully backwash your pool filter and troubleshoot any issues that may arise.


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