Interesting ideas, Poconos!

BTW, I mentioned the problem to the good folks who installed the new liner, and Buster (no kiddin') speculated that the extra suction inlet might be for a water powered cleaner. I've toyed with the idea of connecting the pool vacuum hose to this inlet to see what might happen. If it is indeed plumbed to the main drain, that suction might move the clog to the skimmer box. I can't see how it could hurt.