I am... obsessive about water, let's say. I only have a moment to comment, so I'll get right to it and will come back with a better reply if I remember.
I start with Reverse Osmosis water. I start with 5% of the numbers from El Toro Water District's annual report (because my RO system gets TDS to about 5% of normal). You could also just assume everything is 0 across the board.
I used to use 3 separate spreadsheets, all of which I have modified over time for my own setup.
Now I use 0 spreadsheets and rely on Brewer's Friend:
http://www.brewersfriend.com/homebrew/mywatercalcs/
I get my ratios right according to whatever flavors I'm going for. I tend not to go more than 2:1 or 1:2 sulfate/chloride ratio.
I do make sure Magnesium is at 10 or so and calcium is at 50 or so.
Rules of thumb that I live by:
- Less is more, except when it's not. Aim as low as you can and check your pH during the mash. Aiming low allows for more adjustments to take place during the mash.
- Calcium should be 50-150 ppm
- Magnesium 10-30
- Hard cap on Alkalinity as CaCO3 is 300, soft cap is 250
- Sodium should be 0-150 (~100 gives you a nice round flavor, >150 or so and salt comes out)
- Chloride 0-250, 100+ for impact on flavor
- Sulfate 50-150 for most beers, 150-350 for very bitter beers
- I usually just adjust the mash water now and dilute the final profile with however much sparge water I use. If I fall low on calcium, for example, I'll add a little more in the boil
- If you're worried about pH and feel you might have to add too much salt to counteract dark grains, don't mash all of them. If I brew a super dark beer, I sometimes will steep any of the grains that don't need to be in the mash. It will still have impact on the pH going into the fermentor, but not on the mash itself. Or, you can use pickling lime. Much more impact than chalk on pH (MUCH more, don't use much).
Bypass the spreadsheets and use Brewer's Friend. It'll save you time and headaches. I spent years with spreadsheets and find that their calculator is nearly as good and a lot more straightforward.
Oh, also... you can get a sense for the impact salts will have on a final beer by adjusting a completed beer with them. Just do a few calculations and add a little chloride, sulfate, and sodium in different amounts.
