I have a friend who wants me to help with his pool/spa plumbing.
I am having trouble figuring out, one thing.
He is switching from 2 pumps to 1 pump for a spa/pool combo. The spa has a higher water level.
A check valve on the spa return line would stop the water from draining back, when the spa is off. But what can be done on the suction.
Do I assume the 3 way valve is only going to be on full spa/or full pool.