Leak 💦

[Mdwright72]

I’ll keep this brief. Super old (1960s) cement pool. Return lines are encased in the cement with about 5 feet of pvc that was new in 2014 taking the water to the pump house.

2 weeks ago started losing 2-3 inches every night. Currently isolated to the main drain. Plugged it with a rubber expanding plug. Lost 2” overnight!! No visible cracks and painted the whole thing with pond shield last summer and looks good.
Thoughts on if:
A. Rubber plug just not working? Is there a way to non-permanently seal the whole thing or put a solid cover on it? Or
B. Could it be leaking around the mouth of the main drain? Is that possible with everything encased in cement?
C. Any other wild a** guesses?
This pool has been good as gold for years....

 

[Brett S]

Currently isolated to the main drain.

What exactly do you mean by this? You have isolated the leak to the main drain? If so, how have you determined that?

Or do you mean that the pool is currently only running on the main drain?

 

[Mdwright72]

Done the bucket test and a variety of other things with the equipment and returns and skimmer. Now only have water in the deep well, no equipment running for 2 weeks and still leaking. If not the main drain it would be the shell, which is cement and showing no cracks.