Leak-Next step suggestions

[jmbuys]

Reviewed the TFP FAQ for finding leaks and after some research looking for suggested next steps:
-Did bucket measure to verify water loss over 1 week period: Pool lost 4.5 inches of water over the week (this is above and beyond evaporation).
-Over the week I ran the pump 12 hours on/12 hours off
-80% of the 4.5 inch loss occurred during the 12 hours the pump was OFF, 20% of the loss occurred while the pump was ON
-Using the TFP guide I checked all items on the equipment pad for any leaks at connections. air loss, lubed o-ring on pump...all items mentioned in the guide: I'm 99.9% sure no leak at pad
-Turned off pump and carefully checked inside the pool using a leak dye for any leaks in the lining, around light, returns, skimmer, main drain and vinyl overlaps. Found no leaks but it's a large area so can only say ~80% sure no leaks in the pool itself

From that background it seems most likely the main culprit for the water loss in 1 of the 2 suction side lines -does that sound reasonable? If so would you suggest next step be a pressure test of the suction lines (main drain and side skimmer)? Then assuming pressure test revels a line w/ a leak how is that best rectified? Run a new line?

Thanks

 

[almostakeeper]

close off all skimmers and returns at the pool to see if the water loss changes. Watched a video where a leak specialist, using a listening device, pinpointed the exact spot above a leaking line.

 

[jmbuys]

tried this last night....no real water loss. so still leaves me thinking it's either the main drain line or the skimmer line......can pressure test them but then I have no idea what is the best method to address where the leak might be along the line and how to fix (try to fix specific area vs have a new line run), and if running a new line is best no idea what's involved in how to run a new main drain line (if it's that one)......both fixes not in my wheelhouse so would have to find a pool guy.

 

[almostakeeper]

I would call a leak specialist that has the listening device to hear the leak. Tunnel straight down and fix it. Pretty straight forward. If the leak is bad maybe a plumber with a camera/snake outfit. Good luck.

 

[jmbuys]

Ok so we did pressure tests, leak is in main drain. So pool guy said they normally just cap the main drain, problem solved (which at first sounds great....no digging etc)...but there must be some negative consequences to this? pool has 2 suction lines (skimmer main drain) and 2 returns...if main is capped then the only suction line is the 1 skimmer (before we moved in the 2nd skimmer was closed because of another leak years ago). Since lots of chemicals go into deep end of pool not having the main drain causes a problem no? also will all the flow going thru 1 skimmer line cause extra stress?