At Doheny's we spend a lot of time communicating to pool owners the best DIY tips for keeping their swimming pools sparkling clean. This includes everything from how to properly balance pool chemicals to how to maintain pool equipment. One of the most important pieces of pool equipment that we talk about is the pool filter. In this post we will discuss how to clean your pool’s cartridge filter so it will last longer and keep your pool water clean and free of contaminants.

What is a Cartridge Filter?

The three most common types of pool filters are sand filters, diatomaceous earth (DE) filters, and cartridge filters. Cartridge filters are different from the other two types of filters because they cannot be backwashed and must always be cleaned by hand. This is because cartridge filters use cylindrical cartridges containing accordion folded polyester fabric in the filtration process. When the pool water is pushed through the filter by the pool pump, it flows through the fabric and debris is trapped in the pleats, leaving clean, clear water to return to your pool. Since these cartridges are constantly trapping debris, they can become clogged with a buildup of dirt, lotions and body oils, so it only makes sense that they need regular cleaning.

When to Clean a Cartridge Pool Filter

Ideally, filter cleaning should be a regular part of your pool maintenance schedule. Hose off the filters once a month or more frequently after heavy use, algae blooms, or major storms. If you notice that your pool filter’s pressure gauge is 8-10 psi over the normal reading, this is another good indicator that it’s time to clean your filter cartridges. At least twice a year it is a good idea to clean your cartridges with a filter cleaner. 

Supplies Needed to Clean a Cartridge Filter

We recommend keeping the following supplies for cleaning your pool filter on hand at all times so you are ready to take action any time the filter is not functioning properly.

Steps to Clean a Cartridge Pool Filter

  1. Turn your pool pump off at the breaker.
  2. Slowly open the air relief valve (usually located on top of the filter) to release any air from the filter system.
  3. Open the drain plug at the bottom of the filter to drain any water.
  4. Follow instructions in your owner’s manual to remove the filter lid by loosening the clamp around the center of the housing.
  5. Remove the cartridges and set them aside. Inspect each one for damage. If you find cracks or tears, or if the cartridge does not feel stiff, it is time to replace it.
  6. Use your garden hose with the spray nozzle attachment to clean each cartridge, taking care to get in between the pleats. Do not use a pressure washer for this step, as it will damage the cartridges.
  7. At least twice a year, thoroughly spray each cartridge with filter cleaner, then rinse thoroughly with a garden hose. For extra dirty filters, soak cartridges overnight in a clean bucket or trash can containing a cleaning solution of one part filter cleaner and three parts water. After soaking, rinse the clean cartridges thoroughly.  
  8. Check the filter tank O-ring for damage. If it is rotted, cracked, misshapen or worn, replace it. Lightly apply lubricant to the O-ring before reassembling the unit.
  9. Return the cartridges to the filter unit and make sure they are securely in place.
  10. Replace the lid and tighten the clamp, ensuring it is properly sealed.
  11. Keeping the air relief valve open and the drain plug closed, turn the pool pump on. Once a steady stream of water flows from the air relief valve, close it.
  12. Check the filter pressure to be sure it is back in normal range.

We always say you can’t have a clean pool without a clean filter. Whether you have an above ground pool or an inground pool, Doheny’s has everything you need to keep your swimming pool and pool equipment in great shape. Call our pool care experts today at 800-547-7665, or check out our website at doheny.com to shop our huge selection of pool equipment and supplies.