I am working on a very large and complicated residential swimming pool which is leaking down approximately 3/4″ per day. Most of the plumbing in this pool has been pressure tested with no evidence of leaking. I am suspecting that there is some type of structural leak under approximately 50 ot 60 feet of stone where water cascades down into the pool. This stone work rises as high as 15 feet above the water level of the pool. This pool has a total of 16 pumps, including 10 large feature pumps, a Paramont floor cleaning system with approximately 50 cleaning heads. The rate of loss is consistant with the pumps running or not running.