If your pool has a diatomaceous earth (DE), cartridge or sand filter, backwashing should be a regular part of your monthly pool maintenance. Backwashing is a quick and sustainable way to remove dirt and organic matter that gets trapped in your pool filter from everyday use allowing for cleaner pool water.

What is Backwashing?

Backwashing is the process of reversing the normal flow of water through your swimming pool filter. This allows debris that may get caught and built up to be removed from the filter entirely. The water comes from your pool, flows through your filter counter to the normal flow and then travels through a backwash hose to be released in your yard or designated area.

When Should I Backwash?

You should backwash at any point that the pressure gauge on your pool filter reads greater than 8 psi over the baseline pressure which is the pressure when the filter is clean. The pressure gauge should be located between the pump and the filter, and many times is located on the filter housing. A high psi on your filter is an indication that the buildup is forcing the filter to work harder than ideal. By backwashing your filter, you will see that the water is flowing through your filter easier, and you will enjoy a clean pool. The pressure of your pool filter should be checked on a monthly basis.

What are the Steps to Backwashing?

1. Ensure that your pump and pool system is turned off.
2. Depending on you pool plumbing you need to attach your backwash hose to the water clamp.
3. Set the valve handle to backwashing mode. Most pool filters have a push-pull valve or a selectable lever, but you may need to consult the owner’s manual for your particular model. (The standard settings of the valve are listed below.)
4. Turn your pool filter back on. You should begin seeing the water come through the backwashing hose. The water will likely be murky.
5. Allow 3-5 minutes to pass or at least until the water is coming out clear.
6. Turn off your pump and system again, and set the valve handle back to its normal filter position. Your filter may have a rinse setting which you can also run the water through before turning the pump off again.
7. Turn the pump back on and open the air relief valve at the top of your filter. Allow this air valve to remain open until all the air in the system is purged and the water is flowing at a consistent rate and then close the valve.
8. If the type of filter you have is a diatomaceous earth (DE) you will need to replace the DE powder that will be removed with the backwashing. The amount of replacement powder will depend on the size of your filter and you should check the user manual. The replacement powder should be loaded in the pool skimmer immediately after the pool is put back into normal operation, as you can damage the filter elements without the DE powder.

Push-Pull Backwashing Valves

While the mode of the valve position may differ depending on model, generally they are as follows:

Sand Filter

Backwashing – Down position

Filter (Normal) – Up position

DE Filter

Backwashing – Up position

Filter (Normal) – Down position

Multiport Backwashing Valves

These valves normally have the following positions:

• Filter
• Backwash
• Bypass
• Waste
• Closed
• Rinse
• Recirculate

What are the Risks of Backwashing Myself?

Backwashing is a pretty simple process, but it does take time and can often be a dirty task. The biggest risk in backwashing is blowing a gasket by not turning the pump off. You may also be using rinses or cleansers that are not compatible with your type of filter. At South Austin Pool Cleaning, we preform backwashing on a regular basis and have all the necessary equipment to perform this maintenance on your pool.

Even though you perform regular backwashing your filter, periodically you will need to open the filter and clean the filter manually and/or change the filter elements.

About the Author: South Austin Pool Cleaning is the #1 pool cleaning and Maintenance Company in Austin. Servicing homes from South Austin to Lakeway, we can make your pool the envy of the neighborhood! We always offer free inspections, so call today!