This will be my first closing and have been studying the how to's. I'm now focusing on making sure I understand how to properly clear lines of water and am looking for this site to confirm that I'm on the right page.
I am planning to drain water to a couple inches below returns. Since my skimmer and returns won't be under water, can I then take the air compressor and blow out skimmer from the skimmer side? And can I stick compressor hose in each return line and blow?
Or, is it best to plug compressor into pump basket and blow out from pump to skimmer/return? I guess I'm also confused on how the air will make it from the pump, through the sand filter to the returns. I imagine I'll need to blow air from the pump to the main drain. How do you isolate the main drain? I thought as a safeguard, isolating the main drain isn't allowed.
Sorry for my confusion. Part of the problem is that of the 3 plumbing control valves, I've only been able to determine that closing 2 of the 3 valves isolates one of the two skimmers for vaccuming. Ohterwise, I don't see a difference when I have the 3rd valve open or closed.