New guy here, been reading and learning a lot about pool leaks but I can't figure out what's going on with mine. Water level is fine with the pump off. It drops when it's on, so I changed all the gaskets and o-rings of the backwash valve, which haven't been changed in who knows how long. We ran the pump afterward for 24 hours straight and the water didn't drop anymore, I thought that was that. But a couple days after running the pump on the regular timer, it's dropping again. What the heck is going on? There aren't water drips around the pump equipment. The pool plumbing is connected directly to the sewer line, we don't have a backwash line that I could see if water is dripping out.
Pentair WhisperFlo pump