Well, as the name suggests, backwashing involves reversing the flow of water through your filter media, be it Zeoplus, sand, glass pearls or diatomaceous earth (DE). This dislodges dirt and debris that may have become trapped, and flushes it out through your multiport valve waste line.
When should I backwash my pool?
As a general rule, you should be backwashing your pool about once a week or in conjugation with your scheduled maintenance. Another industry standard is to backwash when your filter's pressure gauge reads 8-10 PSI (pounds per square inch) over the starting level or “clean” pressure.
Is backwashing a pool necessary?
Backwashing and teardown depend on how often you use your swimming pool and just how dirty it actually gets with normal use. DE filters are usually torn down and cleaned at least six times per year. Unless your pool gets really dirty, you should not need to backwash it beyond your scheduled maintenance.