Sometimes the most simple elements are left out of instructions. This has been the case for my understanding of several aspects of the 3-way valve. Thanks for filling that gap for me. And for the great suggestion when cleaning the intake filter. Can you tell us why at 0:38 you did some adjustment to the piece at the top of the valve before changing the setting (which you had not done previously when changing the setting)? Thanks.
The adjustment screw in the middle is to tighten down the 3 way valve ( screwing it clockwise locks it into position so he loosened it to make it easier to move) he should have also not just shut off the inlet to the pump but also closed the return valve as you can see when he opened the filter the pump emptied. I always isolate the whole system from the pool when opening the pump or filter assembly.
