Okay, been doing some testing and planning. My RO product is showing ~8ppm total alkalinity. (Actually that TA is after adding calcium chloride, which may not be pure, may have affected measurement. Titration might have been sloppy too. TDS of permeate on its own is 7ppm.) I'm planning to bring Ca++ to ~50ppm in all my liquor, and add lactic acid to the the mash liquor equivalent to about 2% Sauermalz in the grist. Does anybody think I'll need further acidification of the sparge liquor (assume 100% Pilsner malt)? I want to minimize treatment, but don't want to have the runoff pH rise up too much. I've always brought the sparge liquor to.5.6, but hope not to?