I'm going to eventually need to drain 1/2 my pool in order to bring my calcium levels down. I was wondering if I could just drain via backwashing (DE). I'm hesitant since the manual says not to run the filter without DE for more than 5 minutes, and I'm not sure if backwashing is considered the same as if it were filtering. I don't have a bypass valve, just filter/backwash.

Thanks...