perhaps someone can give me some advice and or help regarding the leak in my pool.
First some information about my pool and if I haven't covered everything, please ask.
location is Saint Louis Missouri (evap chart says .25 to .5 inch drop per day)
in ground pool
built in the late 70's (we've been in this house for 5 years)
about 20K gallons
strange construction... concrete bottom and fiberglass panels for the sides.
concrete skirt (pool deck) around the pool for 6-8 feet, then grass
equipment is about 30 feet away.
equipment is downhill, below level of water, but not below the bottom of the pool.
4 return jets
pump is set to run 24 hours.
About 2 years/18 months ago, we had the pool deck redone and at that time had all of the plumbing replaced, the lights and light shells replaced, an extra skimmer added and the pool equipment moved out of the way. The pool equipment (pump, DE System, multi valve, SWG and power) was all new as of the previous year.
We also had the pool painted.
The guys that did the work, appeared to have trouble with a leak which they worked at for a while and I believe fixed by putting putty around the light(s).
Last year, summer of 2009, we thought the leak was back, so this year when I opened the pool, I drained it down to where the shallow end was completely dry. I then carefully went around and sealed all the panel seams with 3M 5200, also around the light shells, and the skimmer frames on the inside of the pool. I felt very confident (and still do) that if there was a leak around any of those areas it should be gone.
This is the problem:
The pool leaks!!!
If I have the main drain off and the skimmers on, the pool leaks maybe .75 to 1 inch per day.
If I have the skimmers off and the main drain on, the pool leaks maybe 1.25 to 1.5 inches per day. (edited)
I have not tested this with the pump off.
When the skimmers are on, I see bubbles coming out of the return jet nearest the pool equipment.
I have tried the food color dye test on skimmers, lights and jets and there was nothing definitive.
There appear to be no wet areas around the pool, outside of the concrete deck.
I used a post hole digger to dig a hole about 1 foot deep roughly between the pool equipment and the pool and the soil was not wet or abnormally damp.
The pool equipment seems to be running fine and I have good pressure. Before changing DE it is around 30 and after 15 or so.
Other than the leak, everything works fine.
All help appreciated,