Backwash your DE filter when pressure rises 8-10 PSI above clean.

About every 4-6 weeks in peak season, but watch the gauge — don’t guess.

The pressure gauge is your main clue. After you backwash and recharge with fresh DE, note the “clean” pressure (usually around 10-15 PSI). As the filter catches dirt, that pressure climbs. When it hits 8-10 PSI above your clean baseline, it’s time to backwash.

If you go by calendar alone, you’ll either waste water backwashing too often or let the filter get clogged and lose flow. The gauge tells you when the filter is full — that’s the only schedule you need.

One caveat: a sudden jump in pressure (like from 12 to 30) means something broke inside — likely a grid. That’s not a normal backwash call, that’s a tear-down.

The gauge is your filter’s way of telling you it’s full. Listen to it.