Ive noticed recently that the spa goes down by a few inches when the pool kicks on
You can see in the imiage that the spa went down a couple inches recently
It was already low
The pool in this image had been running for 10 min
you can see the wet line in the tired plaster
Is this a check valve issue ?
I hadnt noticed it before because the spa fountain had been on which refills the spa from the pool when the pool is running
I recently turned that valve off