How To Test for Air Leak? (found - tree root grew into line!)

[waste]

Mickey, does your pump have a clear lid? If so, can you see air bubbles in it? Is the water level high enough to feed the skimmer (is a 'waterfall' in the skimmer the reason you want to only run the main drain)? What kind of valve (s) do you have to isolate the skimmer and drain? Sorry for all the questions, but I'll be able to offer better and more specific advice with these answers. Al has offered good advice (what's new ) but I'd like to verify a leak as just a leak shouldn't result in foam across the whole surface. Is there any chance that some detergent got added to the pool? Have you used a 'non-polyquat' algicide?
Welcome to the forum and know that Al, I and all the other members want for you to solve this problem and have nothing but positive experiences with your pool! - Waste

I posted 2 min after you did. As it's a superpump, it does have a clear lid and I have LOTS of experience with them. The 'weir' of the skimmer, should move freely but stay ~ at water level (I can tell you why if you're really interested), if something has jammed it so that it stays fully upright, the skimmer could 'waterfall' causing air in the pump and filter.