I have a pool with a raised spa (approx. 8 ft diameter). My pool runs all day and is off at night. Every morning my spa drops between 2 and 3 inches of water. I have done several tests to try and isolate the problem.
When I plug the spa returns and drain I do not lose any water in the SPA.
When I turn the return valve in my pool for just the spa returns I do not lose any water.
When I close all of the suction and leave the pool and spa returns open I lose water.
When I plug my cleaner return and intake and leave the pool and spa returns open I lose water.
When I put the pool in recirculate mode I do not lose water. I tested this several times
I do not seem to be losing any water out of my waste pipe from my 6 port valve. I just changed the spider gasket because I thought that may have been the problem. I can not find any visible leaks anywhere near the equipment and the pool.
I tried using fix a leak to see if that would help and I am still losing water.
The filter pad sits level to the pool deck and the spa is about 2 feet higher than the pool deck
Could the water be slowly flowing back into the filter during the night if so how can I stop this or is this a leak and I have not been able to find it?