vinyl lined in-ground pool but with a complete concrete shell.
2 skimmers and main drain on bottom all on south end of pool.
Pool pump around 30 feet due west of the western-most skimmer.
3 returns on the norther end of the pool in the walls.
I lost about 6 inches in the last 48 hours with pump NOT running.
I lose it at a faster rate (possibly twice that rate) when the pump is running.
I get some bubbles in the first return when the pump is running.
I've lost 1.5 feet (or so) in 5 days.
Since the pool is concrete lined, a vinyl leak would be contained, would it not? I see no bubbling behind the liner (plus level wouldn't fall.)
I see no noticeable wet spots on the pool-to-pump pipe route.
The route from pump to pool goes under quite a bit of concrete .
The exact routing of the plumbing is not known.
What should my next step be?