When to condition water?

My report is at the bottom. I am a noob. I have trial version of BeerSmith. I see there is a tool to match a given city's profile. I assume that means you just add minerals as prescribed at the beginning, and brew.

In How to Brew I am a bit confused by the mash pH chapter. At first he says just adjust the mash pH after you add your grains. Then he goes on to show how to adjust your water to aim for a target mash pH.

My first basic question is whether all the nomograph stuff in HtB is aimed at preemptively trying to target for a mash pH, or if it is for adjusting.

My water is soft, and sort of like Pilsener, Czech. I am brewing my 3rd batch and I am going to try for a high gravity dark beer.

If I am going to just adjust the mash directly, how/when do I do that? Can I use any pH strip? HtB would seem to recommend using a combo of baking soda and chalk in my case. I guess I have low sodium so at least that allows me to add some baking soda and still keep sodium level in check.

It seems to me that would hit a desired pH, but I am trying a high gravity beer. What about Mg for yeast nutrient? My water is light in so many areas. Perhaps I should be doing some adjustment up front?

Sodium, Na 9
Potassium, K < 1
Calcium, Ca 7
Magnesium, Mg 2
Total Hardness, CaCO3 26
Nitrate, NO3-N 0.2
Sulfate, SO4-S 2
Chloride, Cl 6
Carbonate, CO3 6
Bicarbonate, HCO3 26
Total Alkalinity, CaCO3 31
"<" - Not Det

You should probably ignore most of the water chapter in How to Brew. Your water is excellent for brewing (essentially RO water). For most styles you'll just need to add some CaCl2 and/or Gypsum. The water primer thread (https://www.homebrewtalk.com/f128/brewing-water-chemistry-primer-198460/) gives general guideline amounts based on the style of beer.

edit: To answer your other questions, the nomograph in HtB tries to calculate how much alkalinity water needs based on assuming the pH of the mash is a function of the beer color. While this is roughly true, beer color is only loosely related to the mash pH and this idea is now somewhat outdated.

If you want to directly adjust your mash pH, then the best way to do that is with a pH meter. The strips generally read about 0.2 low for some reason and aren't too reliable. In general you don't want to add alkalinity to your water (baking soda, chalk, pickling lime) unless you're really really sure your mash pH is going to be too low (most of the time it's not unless you're brewing a really dark beer). If you don't want to buy a pH meter, a spreadsheet like Bru'n Water (https://sites.google.com/site/brunwater/) will help you make rough estimates of the mash pH given a particular recipe and your water profile. If you do end up needing to add alkalinity, then pickling lime (Ca(OH)2) is the best way to do that, but measure it carefully - a little goes a long way. Baking soda can also be used, but this adds sodium, which is generally undesirable. Chalk won't dissolve unless you do elaborate things, so it's best avoided.

Magnesium should generally not be added since the malt contains enough of this for the yeast.

Wow, awesome, thanks so much!

You could also steep the steeping grains on your high gravity dark beer after the mash is done.

Be careful with baking soda since you can overdose the sodium that way. Not too tasty. If you don't have pickling lime, I would hold out the roast and crystal malts from the main mash as mentioned above. You can add them at the end of the mash to avoid dropping the mash pH too low during the main saccarification. The best option is to eventually get some pickling lime if you intend to brew darker beers like this.

Oh, another helpful way to avoid dropping the mash pH too far with this clean water is to NOT add any calcium or magnesium-containing minerals to the mash water. Just figure out how much that addition is supposed to be and then add those minerals directly to the kettle. This avoids reducing the mash water's RA and subsequently the mash pH.

Thanks all. Is pickling lime just CaCl? The primer first mentions dihydrate form, what the home brew store sells. Do I take this to mean the little white balls sold as calcium chloride are the dihydrate form, or is pickling lime different? And if so I wonder where to get it.

Pickling lime is Ca(OH)2 - calcium hydroxide. CaCl2 is the chemical symbol for calcium chloride.

Yes, when you buy calcium chloride from the homebrew store it will be the dihydrate form. Pure CaCl2 salt is a desiccant (it wants to absorb water from the air), so unless you keep it tightly sealed from the moment it's produced it will absorb water (becoming the dihydrate form). For brewing this doesn't matter at all since we're just dumping it in water anyway. The only thing is if you weigh out equal amounts of pure CaCl2 and CaCl2 dihydrate you won't have the same amount of calcium and chloride ions since the water in the dihydrate form effects the weight. Most brewing calculators take this into account (i.e. assume you're using CaCl2 dihydrate).