100 F should be ok, I never ran any warmer than that. I think most use cold water, as do I, when I was the tanks at the sugarhouse I use a 1/2" diaphragm pump with 5/8" potable water hose hose, but then it reduces to a 1/2" ball valve and then a few feet of 5/16. I then push hot water at about 100-110 F thru (3.1 gpm), always open discharge.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.