Appreciate your site. Switched to BBB and water sparkles!

I started using DE and a skimmer sock as suggested in the forum and have seen the sand filter full of air after running for a day or two. Found the sock to be cause of air bubbles that were created from the water moving through it.

When the pump shutsdown, this air inside the filter forces water back into the pool through the skimmer along with all of the fine stuff that was caught in the sock.

Is this typical? Thank you.