A before and after picture of a dirty to clean cartridge pool filter

Your pool is a great place to spend an afternoon – until it gets gross and murky. When this happens, you may worry that your expensive pool pump is broken; however, the most common cause of murky water is a dirty pool filter. Just like any other filter in your home, your pool filters will eventually get so clogged with the contaminants it collects that it will no longer be able to work efficiently.

Cleaning your pool filter is important for keeping your water clear, and it’s also necessary if you want to prolong the life of your pool equipment. Your pool may be outfitted with a sand, DE, or cartridge filter. Here’s how to clean each kind:

1. Cleaning a Cartridge Filter

Cartridge filters are a popular option nowadays because they’re so easy to maintain. They typically need to be cleaned 1-3 times a year and replaced every 3 years – although this may vary based on your location and the type of cartridge filter you have. Here’s how to clean a cartridge filter:

  1. Turn off your pool pump so that water ceases to flow through the filter

  2. Locate and remove the drain plug to begin draining the filter tank (opening the air relief valve on the top of your filter will speed up the draining process)

  3. Once draining has ceased, locate the clamp and begin to begin to loosen the nut using a wrench.

  4. Once the filter clamp is removed, you can lift off the pool filter lid and begin to remove the cartridges inside.

  5. Use your garden hose to spray down the individual cartridges, working from top to bottom.

  6. Once your cartridges are free of debris, place them back in the tank and work backwards through the above steps to set the filter in motion again.

2. Backwashing a Sand Filter

Sand filters require the least maintenance, and the sand in them only needs to be replaced every 5-7 years. (in ideal conditions)

There’s no hard and fast rule to how often you should clean your sand filter; the best way to check if it needs cleaning is to occasionally look at the pressure gauge. When the pressure rises significantly, it’s time to backwash the filter. Here’s how:

  1. Turn off the pool pump

  2. Switch your pool filter multiport valve from the filter setting to the backwash setting. This will reverse the flow of the water so that instead of the filter pulling out contaminants from the water, the water will be pushing out contaminants from the filter.

  3. Turn on the pool pump and run it for at least 2 minutes. If you are able to view waste water run until it begins to clear.

  4. Turn off the pool pump, switch the filter valve to the rinse setting, and then turn the pump back on. Run it on this setting for 1-2 minutes or until the water in sight glass clears.

  5. Reset the valve to the filter setting and turn back on the pool pump.

3. Washing a DE Filter

Diatomaceous earth (DE) filters are the best at cleaning water, but they are also the most maintenance-intensive. DE filters need to be cleaned regularly, and they take the longest to clean. Here’s how to do it:

  1. Turn off your pool pump.

  2. Remove drain plug to begin draining the tank. You don’t want to let this drainage to go just anywhere because DE will leave you with a big mess all over your equipment pad.

  3. Locate clamp and remove nut using a wrench.

  4. Remove the lid and then open the tank.

  5. Remove the manifold and then remove each grid from the tray.

  6. Rinse off each of the grids with a garden hose until they’re free of DE and debris.

  7. Place the grids back on the tray starting with the solo small grid.

  8. Put the manifold back on and work backwards from step 5.

  9. Turn the pump on.

  10. Now it’s time to recharge the DE. (See label on filter tank for recommended lbs of DE.)

  11. Before adding the DE, mix it with water in a bucket pouring it down the closest pool skimmer to the equipment.  

If you don’t want to have to constantly deal with pool filter maintenance yourself, call Liquidus Pool Services. They have a whole team of technicians available to clean and maintain your pool on a regular basis. Contact them today to schedule a one-time pool cleaning or regular maintenance.