Confused on Closing IG

[jmjbj_h]

I plan on closing my IG over the weekend. I live in Central Illinois and my water temp is around 65 degrees. I am concerned with my lines freezing. My skimmer and my main drain come to a T before going into my pump. Each has a shut-off valve. I have 2 return lines that T off underground. What is the best way to blow the lines? In what order? Should I be concerned about my Main Drain line because I can't see how you could keep water from not freezing in it? Please help

Joe

[Poconos]

Joe,
There are a bunch of threads and posts relating to main drain issues. Just a couple very recent ones:

http://www.poolforum.com/pf2/showthread.php?t=5912
http://www.poolforum.com/pf2/showthread.php?t=6038

and if you keep digging in this forum you'll find a lot more. I don't have a MD so I'm speaking from what I've read and some knowledge of freezing. The skimmer is the critical thing so that line has to either be dry or filled with RV antifreeze. The water in the MD line certainly has to be removed above ground and below you should lower it as much as possible and then seal the line with the valve. You'll find more details about how you do this in recent past threads.
Al

[waste]

Joe, the trick in 'freeze protecting' the MD is to blow air through the line until you see bubbles, then slam the line shut. It isn't the best way to protect the line, but (unless you care to don SCUBA gear) it's the 'traditional' way of doing it. What you're looking to do is getting the water in that pipe below the 'frost- line' so that the water in it won't freeze and burst the pipe. This is one of the reasons that some builders will not install a MD on their pools.