I have an older indoor pool that's been leaking for a while now. At first I thought it was evaporation. It started to leak more back on Feb/March - it'd lose about 0.75" every 24h. At the same time I noticed air in the pump that would not go away. I'd turn the pump off and in a matter of a few months it lost most of the water. So I drained it to about 2 feet of water and it continues to leak. In my view, the only possible leak sources would be the three floor outlets with returns and drains. There are there total - two in the deepest section and one on the opposite side. I have removed and reinstalled the rubber plugs on all three and filled it with about 1ft of water to cover the bottom - it still continues to leak. I've tried pouring water with die around the outlets yet I can't see any water movement indicative of a leak. Is is possible that it's leaking though the concrete, even though there are no visible cracks? Would the pressure test be the next logical step? Thanks.
- - - Updated - - -
I was trying to attached are a few pics of the outlets but the system doesn't let me.