I listened to a couple of good podcasts on pH from basic brewing radio. The guy mentioned that 5.2 stuff, but suggested that it wasn't all that useful. Essentially it's supposed to be a pH buffer solution (a mixture of both acid and basic compounds which holds pH at a specific level when other acids or bases are added to the solution - up to a specific capacity). There was some (technical) discussion, but the jist of it seemed to be:
1. The grain itself provides a pH buffer for the mash that generally drags it to around the correct pH anyways.
2. Messing with the water pH doesn't really impact the mash pH nearly so much as mash thickness and the specific types of malts selected.
3. If there is too much mash water per grist, the alkalinity you get from municipal water can override the buffer from the malts - hence a thinner mash will increase the pH of the resulting solution past a point.
I really wouldn't worry about it unless your water comes from a real messed up source... Fredericton water is fine, afaik. A quick googling revealed this for you:
http://www.moncton.ca/Assets/Residents+ ... Report.pdfWhich suggests your water is around pH 7-8... for reference; Fredericton's is right about the same. So far as I am aware, the mash pH refers to the pH *after* the grain is added (it's the pH ranges at which the amylases are optimally effective - like the temperature for a and b-amylases, they have different ranges with an overlap).
Original (2 hours!) of discussion is here, but be warned, it's heavy going:
http://www.basicbrewing.com/index.php?page=radioIf you do sit through the whole thing and get something else out of it that I haven't posted above, please throw it down in this thread so that others can benefit without having to go through the same test of endurance.