We're half way through closing our 18,000 gal inground pool here in southern PA. Water levels dropped, blew out & plugged returns, but got seriously stuck at the skimmer/main drain. We have no valves besides the multiport, and the skimmer is NOT a two port deal with a flow diverter plate, but one port with a tube diverter (see "Old Style Anthony Skimmer" http://blog.poolcenter.com/article.aspx?articleid=6327). I can connect a shop vac to the tube in the skimmer and blow out all the returns, and skimmer at the pump pad, but once everything else is closed, no bubbles from the floor drain The pool came with the double rubber stopper, so even if I could force air through, I'd have to shut off the vac, unscrew the diverter, and then slam the rubber stopper in. Any advice?
Here's our setup, to my knowledge (just bought the house):
Anthony 18,000 gal plaster pool, 8 ft deep end, installed in 1986
Main drain and one skimmer, connected as described above
2 returns, ~2 feet below coping (can't drain below them unfortunately)
booster return for Polaris
drain/skimmer goes to main pump, a new Pentair variable speed
that goes to the MPV, then a Pentair DE filter, and back to returns, with the boost pump feeding from the return line.
Our property (and thus the pool) is on a pretty significant grade, so I'm definitely concerned about the frost line. Any advice is greatly appreciated!