I closed my vinyl inground pool at the end of August. The pool measures 16' x 32' and runs 3' - 7' deep. Over the last few weeks I've noticed that the pool cover seemed to be sinking into the pool. Over the weekend I pulled back the cover at the shallow end and it was completely dry and the vinyl liner was beginning to pull away from the corners and bottom edges. I had a local pool tech come inspect the liner, since I thought that there was a hole in it. He claims that the liner has no holes (it was installed in 2002), and that the main drain has a leak in it. (It was built in 1954 by the previous owners) His suggestion was to plug that drain, fill the pool back up and see if the leak stops. Next year when I open the pool, he said that I will only be able to operate the pool using the skimmer (I only have one) Will this be adequate to filter the pool? I've also had issues in the past when trying to vacuum the pool. Normally I would run the filter with the skimmer closed and attach my hose and then turn the valve so that the skimmer is open and the main drain is closed, but sometimes when doing so i lose prime and would open the bottom just a bit to restore prime and then close the valve again. How do i vacuum the pool now that the skimmer is the only thing attached to my filter?