spa level drops overnight

Set up: Pools is salt system, 18,000 gallons, DE Filter. Pool heater. Booster Pump for pool cleaner. Poolside elevated Spa drains (overflows) into pool. A week ago spa water level dropped overnight. Ordered OEM Jandy check valve flapper assy. (I have done this before successfully) Had to...

I have been trying to solve this problem for a month. I have an inground pool, with a spa that is 1ft higher than the pool. During operation water overflows from the spa into the main pool. There are also a set of three beach jets adjusted manual with a value, and three deck jets. Flow to...