I have an above ground pool in the house I'm renting that hadn't been taken care of for years. After removing 1200 lbs (literally) of wet leaves/frogs/dead possum, and draining the pool, I began to refill it from our well. It's a 24'x48" above ground pool with surrounding 18" deck and rails. Nice pool. Liner seems to be essentially pristine. I didn't notice any part of the liner out of the hook when I drained it adn cleaned the leaves out. Everything looked essentially perfect. So the slow process of filling from our well began. In a matter of 2 1/2 days I got the water to about 22" (around 7000 gallons by my guess). While I was at work a 4' section of liner slipped out of the J-hook and sagged down about 4-6". I've tried spraying with hot tap water and stretching - while the liner did stretch I couldn't get it to reseat in the j-channel. There is a small fold in the liner on the floor below the slip, but it's only about 1". I've heard about using a plunger to "suck up" and "push" the crease over to the wall and maybe pull or float the crease upwards - perhaps giving me enough slack to reseat the liner Jchannel. What are my chances of this actually working? I'm trying desperately to avoid draining the pool again.