The suspect return line is on top of the steps in my pool. There are no noticeable air bubbles and I don't seem to be losing a lot of water. The bucket test showed no loss other than evaporation. In the past week I've lost 1/2 to 3/4 inch. So if there is a leak, it must be a small one. The only indication is a small line of sand that runs about 2-3 feet out from where the return line is at the pool bottom. I have 3 returns and only see the sand at this return. It's only there after the pump has been running.
Is there a way to confirm the leak and tell where it is? Unfortunately, I have a concrete deck that covers a good portion of the return that I would prefer not to dig up. Not sure what the next step to figure this out is? Do I need to call a leak detection service?