I'm hoping this is the right place to put this topic. I have a spa attached to my pool that seems to be losing water faster than the pool. As an experiment, I shut off the pump and closed the Jandy valve so that the pool and spa were isolated from each other (no water in or out). I let it sit that way while we were on vacation for 2 weeks, and the water level in the spa is now about 2 inches lower than the pool. The water in the spa is slightly warmer due to it being shallower than the pool, but I haven't heated the spa since starting the experiment.
Is there any way that the spa could be evaporating faster than the pool, or should I assume that there is a leak somewhere?