Hey guys... so many great questions. Glad you're all willing to help.
My pool and spa are at the same inground level. I do have a small spillway between the two in case the spa should overflow. Also,, I want to be able to run in spillway mode during a six month period that we are not on premise to simplify water maintenance during that time... so I will plan a make up valve for that.
I am limited to a 50A service because of loads on my main panel. The automation unit is an "Easytouch Control System 8 for Pool and Spa" (P/N is 520540). The panel needs to serve the pump, a small 240v HWT for an outdoor shower, a 240v blower unit, ignition circuit for the gas heater, and a couple 15-20A 120volt landscape circuits. I might be able to squeeze another pump in, but it would be pushing the limits -- and I prefer one pump if possible (unless it's just a really stupid idea).
The reason I'm avoiding the spillover water system for the other 6 months of the year is we want to be able to heat the spa (about 850 gallons) quickly with our gas heater. The pool is about 7,000 gallons but we're not likely to heat it very often. So, keeping the spa separate from the unheated water of the pool seems like the way to go for efficiency.
Both the pool and the spa have their own skimmers and water autofill valves.
So, my thinking and planning has been to use a single variable speed Pentair pump (I'm thinking 2 HP -- for pool circulation with two waterfalls and the spa with a total of 9 jets) to #1 circulate/filter the pool water and #2 circulate/filter the spa water and then run the spa jets as called for.
I have the Easytouch system installed now, but have yet to purchase the pump(s) filter, blower unit, and heater. So, I'm open to your suggestions. I want to be sure that my Easytouch will do what I want and can be controlled by my Android phone... which gets back to my original question about what I need to add to the Easytouch to do that.
Thanks for all your opinions, suggestions, and ideas. My brain is a sponge right now!
Nate
PS: Here's a link to a video overview of the project:
Back Yard Completion
I can upload pics, but this video gives a better overview. The video does not show the spillway between the spa and baja shelf (but it is there in the final construction). Plus, the pool is not an infinity style. The water line will be a couple inches below the coping.