Re: Engine temp ??
I'd add to it a 30 percent anti-freeze/70 percent tap water mix. Water conducts heat a lot more efficienltly than anti-freeze, and higher concentrates of A/F only reduce the cooling conductivity of the water by reducing the volume of it i the mix.
As far as tap water, I do not use de-mineralized waters, and that is what most altered waters are. A de-mineralized water is, of course, mineral starved, and will eat minerals, like cast iron, aluminum, gaskets, etc. Even with a sacrificial anode, the level of engine parts erosion is high. Another thing I do is run a very specific type of thermostat, used to be available under the Mr. Gasket, and Robertshaw brands as a "pressure balanced" 'stat. These have a barrel shaped valve in them, instead of a flat plate, which can be forced shut at higher flow volumes.
Your system looks set up nicely, It should work well.