D.A., some use citric acid to lower ph. some guy's in my HBC check the ph of the sparge water, and add citric acid to adjust. that way they never have to worry about the sparge going over a ph of 5.8.
i don't bother w/ ph adjustment (but, i use bottled spring water that's been filtered). i was at Real Ale Brewing in Blanco this weekend and asked them what they do to treat their water ph. Brandon (one of the brewers) said, "nothing". they use city water, run through a carbon filter and go to town!
go to www.howtobrew.com
. John Palmer talk's about ph in the mash, treatments, and calculations.......