Avoid a pressure washer on pool filter cartridges.

Gentle water pressure and a dedicated filter cleaner are all you need. A pressure washer will shred the pleats and ruin the cartridge fast.

Cartridge filters are just pleated polyester fabric. Treat them like a delicate reusable coffee filter. Start by hosing off loose debris with a garden hose nozzle set to a fan spray—no jet setting. Hold the nozzle at an angle so you’re blasting dirt out from between the pleats, not driving it deeper.

For deep cleaning, soak the cartridge overnight in a chemical filter cleaner (like one with TSP substitute, not just dish soap). Then rinse again. Don’t scrub with a brush unless you’re very gentle; you can tear the fabric. And never let the cartridge completely dry out before cleaning—dried-on crud is much harder to remove and can weaken the material.

Replace them when the pleats start feeling thin or frayed, usually every 1–2 seasons depending on use.

Be kind to the cartridge and it’ll save you a hundred bucks every year.