Can't get backwash to fully close

I have a twist up or twist down backwash unit.

I fully pull up and twist to turn off. 10% of water still flowing thru the "see thru" pipe. Picture attached.

Any ideas on how to get this unit to fully close.

thanks,
scott

You can either take the valve apart and search for a broken piece or more likely, a bad gasket, or you install a ball valve on the backwash line and keep it closed when your filter is running normally, and open it during backwashing. This will prevent water from leaking out.

Brad
Waterworks Pools