I need help on blowing out lines in inground pool. I've blown out both skimmer lines fine, but am not sure how to isolate the return and main drain. When I tried the main drain, I never saw bubbles. Should I always see bubbles? I just read about laying a string accross the drain to see movement that I think I'll try.
To blow out skimmer line, I put shop vac hose in the hole that feeds water into pump. It didn't occur to me until now that I need to put the hose in the hole that feeds to the filter to blow out return line. Is this correct?