BACKGROUND: Hi. I've maintained my own 21k gallon gunite pool the past 10 years. My pool was built in 1998 and has several issues related to siphoning. You can't stop the pump for any amount of time as it is in a pump house which is a little below the water line of the 1100g spa and quite a bit above the water line of the pool. Because of the way it was plumbed, if you don't have the water coming 100% from the spa, the water in the spa will all drain down into the pool in a matter of a couple hours. Then there's no way to restart/prime the pump until you fill the spa; it must be 80+% full before there's enough pressure to prime any pump. The valve must be on the pool (in from pool) in order to keep the spa overflowing and the pump primed/running. [I know it's messed up by that's the way it is]
I'm looking for an inexpensive way to control a 24vac 3-way valve (i.e. Pentair 263045) so that at night, I can have my 3hp variable speed pump turn off (for a few hrs/night) without the spa water draining to the pool. That will require valve automation to flip it from pool to spa. Does anyone have a cost-effect (i.e. several hundred $s vs thousands) solution? If so, would you detail the equipment please? Thanks!

I'm looking for an inexpensive way to control a 24vac 3-way valve (i.e. Pentair 263045) so that at night, I can have my 3hp variable speed pump turn off (for a few hrs/night) without the spa water draining to the pool. That will require valve automation to flip it from pool to spa. Does anyone have a cost-effect (i.e. several hundred $s vs thousands) solution? If so, would you detail the equipment please? Thanks!
