how to backwash the pool filter


Author: Poolking - Swimming Pool Equipment Manufacturer

A sparkling clean pool is a refreshing delight in the summer months, and keeping the pool filter in optimal working condition is crucial to achieving that clear water. Backwashing the pool filter should be an essential part of your maintenance routine to keep your pool clean and free of debris. Backwashing is a process of reversing the flow of water through the filter to flush out the dirt, debris, and contaminants that have been caught in the filter. In this article, we'll go over the steps you need to follow to backwash your pool filter effectively.

Why is backwashing important in pool maintenance?

Before diving into the process of backwashing, let's understand why it's essential. As a pool owner, you need to understand that the pool filter operates by trapping debris, dirt, and other unwanted materials that accumulate in the water. Over time, these materials build up and restrict the flow of water in the filter, reducing its efficiency. A filter that is not backwashed regularly will allow contaminants, algae, and bacteria to build up, which can cause health problems and damage your pool equipment.

When is the right time to backwash your filter?

Knowing when to backwash your filter is crucial in maintaining an efficient filtration system. A common rule of thumb is to backwash your pool filter when the pressure gauge rises approximately 10 psi above its initial reading. You can check the pressure gauge reading when the filter is clean to determine a baseline measurement. On average, you should backwash your pool filter once a week in peak season, and it's even more crucial after heavy usage, storms, or other events that may cause more debris into your pool.

What materials do you need to backwash your filter?

To backwash your pool filter, you will need a few materials:

- Backwash hose

- A screwdriver or pliers

- Shovel or broom (if necessary)

- Your filter owner's manual (optional)

Step-by-Step Guide to Backwashing Your Pool Filter

Step 1: Turn off the pool pump

Before you start backwashing the filter, you need to turn off the pool pump to prevent damage to the system. Switch off the pump’s power supply and make sure that the pump is off.

Step 2: Clean the skimmer and pump strainer basket.

Remove the pump strainer basket and clean it thoroughly of any debris. Next, clean the skimmer basket, and remove any debris that may affect the backwashing process.

Step 3: Locate your filter's multiport valve

Find the multiport valve attached to your pool filter. The valve is usually located on top of the filter tank or connected to the side of the tank.

Step 4: Adjust valve to backwash mode

Using the owner's manual as a guide, change the filter valve to the "Backwash" position. This will allow the water to flow out of the filter tank instead of getting filtered.

Step 5: Connect the backwash hose

Attach the backwash hose to the pool filter's waste port, which is usually located at the bottom of the multiport valve. Make sure that the hose is secure and tightly connected to prevent water leakage.

Step 6: Turn on the pump

Turn on the pool pump and allow it to run for two to three minutes or until the water runs clear through the backwash hose. Keep an eye on the color of the water to judge when the process is complete.

Step 7: Rinse the filter

After the backwash process is completed, switch the multiport valve to the "Rinse" position, and run the pump again for about one minute. This will clear away any remaining debris from the filter and prevent it from returning back to the pool.

Step 8: Return to filtration mode

Switch the multiport valve to the "Filter" position and turn the pool pump back on. You can now check your filter's pressure gauge and see that it indicates that the filter is running at its optimal pressure.


Backwashing your pool filter may seem daunting at first, but once you follow these simple steps, it becomes a regular part of your pool maintenance routine. Remember, keeping your pool filter in optimal condition will save you time and money down the road, and most importantly, it will provide beautiful, clean, and safe pool water for your enjoyment.


Just tell us your requirements, we can do more than you can imagine.
Send your inquiry

Send your inquiry

Choose a different language
Current language:English