OK, newbie question. I want to close the pool this weekend. I'd like to lower the water level a few inches below the skimmer returns, but have no idea how to lower the water level at the pump. I can set it to waster but where exactly do I hook up the roll-out hose, if anywhere, to get the water out of the pool. For some of you it might be a rudimentary question, I know, and pictures of the equipment are attached. Am I supposed to unscrew the large diameter pipe visible on the left by the multiport? I tried unscrewing it by hand actually, it'a tight, not moving. Thanks for your help.

