In my case I think that I would be better off using Distilled Water...even with alot of crystal malts, the pH gets pretty high with the RA in my water (303ppm)...
For instance I am brewing a Doppelbock this weekend doing a big triple decoction. Here is my recipe I have come up with after reading the Classic Styles Series for a 6 gallon batch...
14lbs Munich I (7SRM)
2lbs Bohemian Pilsner (1.7SRM)
8oz Caramunich I (39SRM)
8oz Caramunich II (57SRM)
2.25 Mittelfruh @ 60mins (4.1%AA)
.35oz Mittelfruh @ 30mins (4.1%AA)
Using distilled water for a 6.15 gallon mash (1.4 quarts/lb)
I am making the following mash additions:
2.5g Calcium Chloride
That gives me 85ppm Calcium, 59ppm Sulfate, 51ppm Chloride, 106 Bicarbonate, RA of 27 annnnnnnd a mash pH of 5.4. That puts me in the ballpark because I am not using heaps of crystal malt that lower the pH of the mash.
Sound about right?