Quote Originally Posted by AndieP
Also am I running a risk with damaging the foundation of the pool since apparently quite a bit of water is being lost underground? Should I just load the pool with bleach and only run the pump enough to circulate it?
I would not claim to be an expert, but I doubt it, if the leak is localized to one spot then it is probably just dispersing into the excavation around the pool and getting absorbed into the ground.

I truly have never really looked at many IG plumbing setups, but is it possible to isolate some things? Can you direct all of your water to certain return jets, and maybe figure out which pipe has the leak? I have done this on large watermain systems (like entire subdivisions) in order to isolate the leak. Also, if you have a stethoscope you can "listen" to the decking and you may be able to hear the leak yourself with the pump on. That is what I would do, of course I would also fix it myself too but I am cheap.