Backwash when the pressure gauge tells you to, not on a schedule.

Don’t backwash on a schedule. Your filter doesn’t care about the day of the week.

The rule is simple: backwash when the pressure gauge reads 8–10 PSI higher than your clean baseline pressure. That baseline is the pressure right after a fresh backwash and recharge. Write it down or remember it. When the needle climbs 8–10 above that, it’s time.

Why not more often? Because backwashing too frequently wastes water and DE powder, and it doesn’t make your pool cleaner. The filter works better when it’s slightly dirty. And if you wait too long, you risk damaging the grids or reducing flow. So check the gauge once a week during swimming season, and let it be your guide.

If your pressure never rises, you might have a broken gauge or a different problem. But for most pools, that 8–10 PSI rise comes every few weeks to a month, depending on use and debris load.

Trust the gauge, not the calendar.