Check the pressure gauge, not the calendar.

There is no universal schedule — backwash when the pressure gauge reads 8–10 PSI above the clean starting pressure.

During peak swim season, that often works out to once every week or two, but it varies with bather load, weather, and how much debris blows in. The gauge is more reliable than a calendar. Backwashing too early wastes DE and water. Backwashing too late strains the pump and hurts filtration.

Take a sharpie and mark 10 PSI above your clean pressure on the gauge face. When the needle hits that line, backwash. When it doesn’t, leave it alone.

Trust the gauge. It’s the one part of pool maintenance that actually tells you the truth.