3 Things to Know About When to Backwash a DE Filter

Backwash when the pressure gauge reads 8–10 psi above the clean baseline The clean baseline is the pressure reading right after you backwash and recharge. Ignore the calendar — the gauge is your only reliable indicator.

Ignore a fixed schedule Heavy use and debris can mean backwashing every few days. Calm weeks can go two weeks or more. Following a set schedule wastes time and effort.

Watch for secondary signs, but trust the gauge Lower water flow from returns, weaker skimmer action, or cloudy water also signal it’s time. But the gauge is your primary indicator. After backwashing, always add fresh DE since the old stuff gets flushed out.