My pool has been open for just about a week now. All was doing well until yesterday when I noticed that I was having air bubbles coming from my returns. This hadn't been the case earlier in the week. I did backflush my sand filter and clean out the basket in the pump (Hayward Super pump) yesterday morning.
I can see bubbles coming into the basket on the pump. I have 2 skimmers and 1 main drain return - I've tried closing each of them in turn and the bubbles continue and in fact they get worse unless all 3 are open. I replaced the gasket under lid today since the one I had looked a little pinched and it didn't help. I pulled out the drain plug to the basket and it looked to be in good shape, I put some teflon tape around it and reinstalled it and it didn't help either.
Any advice to help me figure out this out would be appreciated.