I have a 25,000 gal IG vinyl pool. I began the opening process late last week, and all seems to be going fine except that yesterday we noticed consistent light bubbles coming from the two returns. We have a Hayward 1/2 HP motor on a Rainbow M series 8 cartridge filtration system. Everything in the pool shed looks dry -- no leaks that I can see.
In addition to the two returns we also have a Polaris hook up with a booster pump. Water regularly flows (lightly) through the Polaris return, and we sometimes get bubbles there too. Last year we did find that there was a leak on the Polaris return line. Our local pool guy cut it out and spliced it.
So, any thoughts on where the air is coming in and what I can do to trouble shoot the issue?