How to Clean a Pool Filter: Cartridge, Sand, and DE
Clean your pool filter when the pressure gauge reads about 8 to 10 psi higher than it did right after the last cleaning. For a cartridge filter, turn off the pump, release the pressure, and hose the cartridge off between the pleats. For a sand filter, backwash until the water runs clear, then rinse. For a DE filter, backwash and add fresh DE, and take it apart to clean the grids once or twice a year. In Bakersfield, dust storms and leaf season mean filters need cleaning more often.
How do I know when my filter needs cleaning?
- The pressure gauge reads about 8 to 10 psi above your clean reading.
- Water flow from the return jets is weaker than normal.
- The water is cloudy and won't clear even though chlorine and pH test right.
- You've just had a dust storm, heavy leaf fall, or an algae cleanup.
How do I clean a cartridge filter?
- Step 1: Turn off the pump, and switch off the timer or breaker so it cannot start while the filter is open.
- Step 2: Open the air relief valve on top of the filter to release the pressure.
- Step 3: Remove the lid or clamp band and lift out the cartridge.
- Step 4: Hose it off from the top down, working between the pleats. Use a garden hose nozzle, not a pressure washer, which can tear the fabric.
- Step 5: If the cartridge is oily, greasy, or crusted with scale, soak it in a cartridge cleaner before rinsing again.
- Step 6: Check for torn pleats, cracked end caps, or a cartridge that has gone flat. Those are signs it needs replacing.
- Step 7: Reinstall the cartridge, check the lid O-ring, and close the filter.
- Step 8: Open the air relief valve, start the pump, and close the valve once a steady stream of water comes out. Write down the new clean pressure.
How do I backwash a sand filter?
- Step 1: Turn off the pump.
- Step 2: Turn the multiport valve to Backwash.
- Step 3: Run the pump for 2 to 3 minutes, until the water in the sight glass runs clear.
- Step 4: Turn off the pump and set the valve to Rinse. Run it for about 30 to 60 seconds to resettle the sand.
- Step 5: Turn off the pump, set the valve back to Filter, and restart. Write down the new clean pressure.
How do I clean a DE filter?
- Step 1: Backwash the same way as a sand filter until the water runs clear.
- Step 2: Add fresh DE powder through the skimmer with the pump running, using the amount on your filter label.
- Step 3: Once or twice a year, take the filter apart and hose off the grids.
- Step 4: Check the grids for tears while they are out. DE powder blowing back into the pool usually means a torn grid.
When should I call for help?
Call us or come in if the pressure is still high right after a good cleaning, if sand or DE is blowing back into the pool, if the filter tank or valve is leaking, or if the multiport handle is stuck. Top Dog repairs filters and installs new ones, including Sta-Rite modular media filters. If you'd rather have us come to you, a service visit starts with a $139 diagnostic fee. It covers our fuel and travel time, diagnosing your pool equipment, and a written work order for your approval. The fee doesn't cover any repairs.
How often should I clean a cartridge filter?
Clean it whenever the pressure rises about 8 to 10 psi above your clean reading. For many Bakersfield pools that means every month or two during swim season, and more often after dust storms or an algae cleanup.
Can I pressure wash a pool filter cartridge?
No. A pressure washer can tear the filter fabric and shorten the life of the cartridge. A regular garden hose nozzle works best.
How often should I replace a filter cartridge?
Many cartridges last one to three years, depending on how hard they work. Replace one when the pleats are torn or flattened, the end caps crack, or it won't hold a normal pressure even right after cleaning.
Why is my filter pressure high right after cleaning?
The cartridge may be clogged with oils or scale that hosing won't remove, a return valve may be partly closed, or something past the filter may be blocked. If a soak in cartridge cleaner doesn't bring the pressure down, have us take a look.
Don't cry, we can help
Bring a water sample to Top Dog Pool Supply. Local pool owners get a free water test on our Taylor Xpress Flex system, and we'll tell you what to add, and how much, for your pool's size.
Visit us at 7440 District Blvd Suite B, Bakersfield, CA 93313, or call (661) 664-9000. We're open Monday to Friday 9 to 5, Saturday 9 to 4, and Sundays 10 to 4 from April through September.
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