Brewcipher and Bru'n Water final profiles

The answer you're attributing to Bru'n Water would be correct for 1.19 grams of CaCl2 rather than 0.9 grams. (And 0.5 grams of gypsum.)

I'm not too familiar with Bru'n Water, but could it be that your "starting water profile" (or whatever it's called in Bru'n Water) already has some Ca and Cl in it? Or could you have typed 1.19 instead of 0.9?

 

I'm not at my computer, but another thing to look at is whether you've checked the box in Bru'n Water for "anhydrous" calcium chloride or whatever on the page for salt additions. Sorry, without it in front of me I can't remember exactly what the box says, but the short story is that calcium chloride comes in different types and they provide different amounts of chloride per unit of weight. Anyway I suggest playing around with that and seeing if it explains the difference.

 

@minderbender good call on the anyhydrous CaCl2. I don't have Bru'nwater on my current computer, but back of the envelope math tells me the Bru'nwater numbers @Curmudgeon posted are consistent with the anhydrous form.

The thing about anhydrous salts is that they are harder to find, more expensive, and don't stay anhydrous unless you go to lengths to keep them/restore them that way.

 

If you want to get 150 ppm Cl and 100 ppm S04, and you want to use just CaCl2 and CaSO4, you'll have to accept more than 75 ppm of Ca.

Assuming you're treating 8 gallons of distilled water, 9.45 grams of CaCl2 and 5.44 grams of CaSO4 would yield:
Ca: 127 ppm
Cl: 150 ppm
SO4: 100 ppm

If you don't want that much Ca, the only way I can think of to hit all your targets is to get some of your Cl and/or SO4 from Magnesium salts (Magnesium chloride or Magnesium Sulfate (epsom salts)). For example...

Assuming 8 gallons of distilled water, 3.7 grams CaCl2, 5.44 grams CaSO4, and 7.9 grams MgCl2 (epsom salts) would yield:

Ca: 75 ppm
Mg: 31 ppm
Cl: 150 ppm
SO4: 100 ppm

Personally, I don't particularly like Mg in my beers, so if I wanted the Cl and SO4 concentrations you specified, I'd settle for the higher Ca concentration rather than add Magnesium salts.

ETA: This discussion brings up something that a lot of people don't realize (or even think about, because it's a little nerdy), which is that while notional profiles are great, some of them are not possible. The anions and cations have to balance.

ETA more: I suppose you could also limit the Ca and get all the Cl you want by adding some NaCl (table salt) instead of MgCL2. But I wouldn't do that unless I thought the recipe needs some sodium for flavor.

 

Dang, too late to edit.

Note that "7.9 grams MgCl2 (epsom salts) would yield:" should say "7.9 grams MgCl2 (magnesium chloride) would yield:"

 

The supporter version of Bru'n Water does actually have an "Overall finished water profile" read out.

Also, on the anhydrous vs. dihydrate forms of calcium chloride, Martin notes in Bru'n Water: "...selecting dihydrate may overdose the water with calcium and chloride if the mineral has some anhydrous form in it. It may be safer to select anhydrous in order to avoid overdosing." Also came across his response here: https://www.homebrewersassociation.org/forum/index.php?topic=23459.msg299449#msg299449

Confirming what Vikeman noted, I just plugged in your numbers to Bru'in Water and with dihydrate set the two spreadsheets basically match, going with anhyrdrous, Bru'in Water pops up to the higher concentrations.