I have an in ground (shotcrete/gunite?) pool with an elevates spa w/waterfall. the spa has developed a water leak, and through the process of elimination, I have narrowed it down to somewhere between the jets and the water and air supply lines that exit the wall in the back of the spa.
I have let the pool/spa sit overnight, and the water in the spa will fall to the lowest spa jet. Of course, when the pump comes on, the spa return line will refill the spa and allow turnover via the waterfall. After 2 days of this, I have to add water to the pool or the water level will fall below the skimmers in the pool. If I pull the spa jet eyeballs, and put plugs in their place, I stop losing water.
I thought the pipes running to the equipment area about 15' away were possibly broken, as the previous owner (who put the pool in) planted a Yaupon Holly tree right over the pipes. Very nice tree, but they do put out some big roots. Anyway- I dont see any water anywhere around the spa, no obvious wet ground, but most of it is buried underground, and has shrubbery around it. I removed the shrub over the area where the pipes exit the spa and dug down to expose them. There was some spa flex coming out the gunite, and transitioning to regular PVC.
Since I suspected broken pipes/joints, I cut the water line for the jets and put a ball valve as close to the tub as possible. turning the valve to "off", I removed the plugs in the jets and let the spa sit. Still lost water. I then cut the the air line and rerouted it to the air pump. Removed the plugs, used the spa, and when I shut it down, I turned off the valve on the water supply to the jets and left it overnight. Again, lost water in the spa.
I don't see any obvious leaks, no water puddling anywhere, no wet ground around the pipes behind the spa. knowing that the water supply line is shut off at the spa, and the air line is new and not leaking, I conclude the leak has to be between the jets and the lines coming out the back of the spa.
As I understand the construction, a rebar frame is made in the hole, spa jet manifolds are placed with stems out to the spa interior, spa flax is used for both the water and air supply to the manifolds, and when everything is in place, shotcrete is placed to form the floor and walls of the spa, so the manifolds and spa flex hose are encased in "concrete". I suppose there could be voids in this area around the manifolds and/or spa flex hose if care is not taken when filling the forms or spraying in the "crete", and possibly a leak could develop there? is there anything in the jets themselves- a seal of some sort-that might need replacing?
I'm open to any comments, questions, suggestions. I have reached the age where I could really use this spa, but I don't have thousands to throw at it. Any help is appreciated.
For the record: 25,000 gal in ground plaster pool, 1,500 gal (?) attached spa, shares a single 2hp pump with DE filter and gas heater. Dallas, Texas area. Pool is approximately 30 years old.