okay so I decided to do a half drain of the pool. Haven't found documentation for the pump so I'm not sure what the settings on the second and fourth picture are. Usually when its been drained before we'd simply hook a hose into the skimmer hole shown above, twisted the plug on the filter canister open, pulled up the lever shown in the fourth picture and turn on the filter pump. Driven by the pump water would flow through to some drain that led to the sewer.
Unfortunately doing it this way it seemed to me that it wouldn't work when the water level got more than a couple feet lower and I'm afraid if the hose somehow popped off and water stopped coming into the filter the pump might be damaged.
There is a drain at the bottom of the pool. I was wondering if with this setup there would be a way to drain the pool without having to turn the filter pump on and risk damaging it. Is there a setting I could switch between depending upon whether I wanted to wash out the DE or not wash it out with the draining water?