Keep the pressure washer away from your cartridge filter

A garden hose is better — high pressure will wreck the filter media.

Cartridge filters are pleated fabric, not concrete. When you hit them with a pressure washer, the water blasts dirt deeper into the pleats and fibers, where it gets trapped and will never rinse out. You end up with a clean-looking filter that actually performs worse than before. High pressure can also tear the pleats or separate the media from the end caps, which means a new filter sooner than you wanted.

A garden hose with a fan nozzle is plenty. Rinse at an angle, not straight into the pleats, and work top to bottom so the debris washes off the surface instead of into it. If the cartridge is really caked with oil or sunscreen scum, soak it in a filter cleaner first, then hose it off. That does more than any pressure washer ever will.

The pressure washer is great for the driveway. The cartridge filter is where it goes to do