When should I backwash a DE filter?

Backwash when the pressure rises 8–10 psi above clean starting pressure. No weekly schedule. Turn off the pump, roll to backwash, run for two minutes until water clears, then rinse for 30 seconds, and return to filter. Add fresh DE through the skimmer. Don’t over-backwash—the filter works better with some dirt cake on the grids.