A buddy and I are brewing our first Czech Dark Lager tomorrow morning. We're starting with RO water, so we can build it however we need to.
I know the general idea for most lagers is to keep the water soft / low-mineral as much as possible. I'm also under the impression that as a general rule we probably want to have at least 30 - 50ppm of calcium for fermentation purposes, and around 30ppm of chloride as a flavor baseline. (We brew no-sparge BIAB, so all the salts will be added to the full amount of mash water prior to dough-in.)
Where I am right now is 46ppm calcium, 13ppm sulfate, and 34ppm chloride, with a predicted 5.4 mash pH.
Does this sound like a reasonable starting point for the first attempt?
I should mention that, if I'm going to err one way or the other, I will always prefer my beers to be drier/sharper rather than more "rounded".
Thanks in advance for any guidance!