Arizona Home Inspector on Backwashing your Pool

When should you backwash your pool?

People always want to hear an answer like once a week, once every other week, or even once a month, and they are surprised when I tell them it depends on the pressure of your filter system. For starters you have to make sure you have a working pressure guage on your filter. It is usually mounted on the top of the filter and looks like the picture to the right. The pressure usually runs around the 10-13 psi (pounds per square inch) when the filter is clean. You should backwash your pool when the pressure increases by 10-12 psi. EXAMPLE: When your system is first started or clean and you turn your pump on, you can see that your normal operating pressure is 12 psi. You check the pressure daily and it slowly rises and after 10 days the pressure is at 22 psi. Because of the difference in the current pressure (22 psi) and your normal operating pressure (12 psi) is equal to 10 psi, now would be a good time to backwash your pool.

Here in Arizona you will find that during the monsoon season, you will have to backwash your pool more often because of the dirt that blows into pools. During the winter months you may have to backwash only once a month. Therfore, it is no set time, it all depends on the pressure differential.

There are to many different valve configurations to tell you how to backwash your pool so read the owners manual. If you no longer have a manual you can always go online and find the manual or instructions on how to backwash your pool. Read and Follow all Safety Rules because you are dealing with a pressurized system which can cause serious injuries.

Keep in mind that Cartridge Filters dont get backwashed, you simply pull out the cartridges and hose them off until clean or replace them if they are in really bad shape.