I brew on a EHERMS. My HLT is a 20gal blichmann with a SS coil. I need to fill it up with 13 gal of water to cover the coil. My water PH is 8.1:(. I cut my mash with RO and add salts. Question is is there any other way I can bring my HLT/sparge water down to a good PH level without cutting it with RO. My water profile is 66ca, 20mg, 27na, 18cl, 36 sulfate, 262 bicarbonate. I have added latic attempting to decrease the PH but soon learned that the buffeting of my hard water prevented my PH from changing
I used to have the same problem with high bicarbonate water. You want your sparge water to be more acidic and well below 6, and that's difficult to do without the acid additions. The problem I ran into, is that I had to use higher than desirable levels of lactic acid to achieve a 5.5 ph, and I noticed a twang in my beers that shouldn't have a tart twang to them.
I have since switched to all RO water for my brewing. IMO, either use RO or distilled to knock down your waters buffering capacity...otherwise you may not be happy with the finished product- whether that's tartness or twang from the lactic, or tannin extraction.