How To Backwash a Pool Cartridge Filter

This guide discusses the procedure for cleaning a Pool Cartridge Filter.The purpose of a pool cartridge filter is to clean your pool water by capturing debris and decontaminates in the folds of the filter. With time these folds will become clogged, water will not flow thru the filter as easily, and pressure within the filter will increase. Operationally, with water flow down, you will not be turning you pool water as frequently and your pool decontaminates will start to build up. It's time to clean your filter. As a general rule of thumb, your filter should be clean at least once a month during the summer and every other month if your pool is operational during the winter. Although this description is specific to a Hayward cartridge filter, many of the steps can apply to other models of cartridge filters.

1. The first step is to turn off the pool pump to stop the flow of water through the pool filter.

2. Next, you will have to relieve the pressure that has built up in the pool filter. Note the pressure on the pressure gauge. It will typically read between 15 - 20 psi. To relieve pressure turn the air relief valve on top of the filter counterclockwise. Water will spray out initially as you see the pressure on the pressure gauge go to 0 psi.

3. To access the pool filter cartridge you will have to take the pool filter head off the top of the filter. Turn the locking knob counter clockwise until you feel the pool filter head is loose.

4. Next lift the pool filter head off the top of the filter. It may be a little hard to lift initially as you break the O-ring seal between the two pool filter parts.

5. With the pool filter head off, you will see the top of the pool filter cartridge.

6. Lift the pool filter cartridge straight up to remove it from the pool filter body.

7. Set the filter cartridge on the lawn and begin cleaning it with a garden hose. Use a full stray nozzle. A pressure nozzle may be too strong and will cause unnecessary wear on the pleated folds. When spraying, start at the top of the cartridge.

8. Work your way straight down the cartridge to work the debris down and out the bottom of the pool filter cartridge.

9. Rotate the filter cartridge to the next section and starting at the top work your way down again to the bottom. Continue rotating until the filter cartridge looks clean. Check inside the folds to make sure all the debris has been removed.

10. Some of the debris will have collected at the bottom. Spend extra time spraying out the bottom.

11. When you've finished cleaning the pool filter cartridge, replace the cartridge by placing it straight down into the filter.

12. It's always a good practice to lubricate the pool filter head O-ring before replacing the filter head. Lubrication will ensure a better fit and extend the life of the O-ring. Rub a thin coat of lubrication on the outside of the O-ring.

13. Replace the pool filter head on top of the pool filter. Position the top so that you can read the pressure gauge.

14. When replacing the filter top, watch that the O-ring doesn't bulge out of its grove. This becomes more of a problem as the O-ring becomes older and stretches. If the O-ring is not set properly the top will not close correctly and water will spray out when the pump is restarted. The O-ring should be replaced if this is a recurring problem.

15. Hand tighten the locking knob clockwise.

16. Turn on power to the pool pump to repressurize the pool filter.

17. The air relief valve should still be open. As the pressure builds, air will be released through the relief valve. When water starts to spray out of the valve, turn the valve clockwise to close it.

18. Check the pressure gauge. It typically reads between 10 - 15 psi but this will vary according to the make of pool cartridge filter or its age. This value is your system's clean filter pressure. When the pressure is 8-10 psi higher, it's time to clean your pool filter again.

If you have any other questions about pool and spa products please do let us know - we are here to help!

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