3 Things to Know About Backwashing a DE Filter

Backwash when the pressure gauge reads 8–10 PSI above your clean baseline pressure. This is the only reliable rule for DE filters. Guessing or using a calendar schedule wastes water or stresses the pump.

A fixed schedule doesn’t work because DE filters fill up at different rates. Swimming frequency, heat, and debris all affect how fast pressure builds. On heavy-use weeks you might need to backwash every few days; on quiet weeks, every two weeks.

Always add fresh DE through the skimmer after backwashing. Without fresh DE, the filter won’t trap debris effectively. The gauge tells you when, but you have to replenish the media.