Pool Cartridge Filter Guide — How to Clean, When to Replace

To clean a pool cartridge filter: (1) Turn off the pump and release pressure via the air relief valve. (2) Remove the filter lid and lift out the cartridge(s). (3) Rinse with a garden hose at a 45-degree angle from top to bottom, working between the pleats. Do not use a pressure washer — it damages the pleats. (4) For a deep clean, soak overnight in a filter cleaning solution diluted in water. (5) Rinse clean, reinstall, and start the pump. Clean the air relief until water flows, then close it.

Clean when your filter pressure gauge reads 8–10 PSI above the clean baseline. For an average residential pool, this typically means every 2–6 weeks in summer. Heavily used pools, pools in wooded areas, or pools that recently had an algae bloom may need cleaning every 1–2 weeks.

No. Cartridge filters do not have a backwash valve. They are cleaned by removing the cartridge and hosing it down or soaking it in cleaning solution. Some pool owners confuse "cartridge filter" with the filter basket on their pump — that basket is cleaned separately and does not affect the cartridge.

A pool cartridge filter element typically lasts 2–5 years with proper maintenance. Signs it needs replacing: pleats are visibly cracked or crushed, cleaning no longer brings pressure back to baseline, or the cartridge has a permanent grey or brown discoloration that does not wash out. Cheap replacement cartridges from off-brand suppliers often last under 1 year.