crookedeyeboy wrote:Aleman wrote:crookedeyeboy wrote:28.34g (1oz) of sodium carbonate (not bicarb) = 163ppm of alkalinity per brewers barrel (163lts)
For 23lt brewlength: 163 / 23 = 7.08
28.34 / 7.08 = 3.99g per 23 lts of beer to be made will add 163ppm of alkalinity.
Jobs a good un as they say

Unless you are trying to avoid adding sodium

Use Calcium Carbonate is you don't want to add Sodium. Just slightly different maths.
Quite a bit different, and calcium carbonate is not all that soluble in plain water or indeed in the mash as I suspect that the calcium carbonate particles act as deposition sites for calcium phosphate, which is even less soluble, leaving you will still a high mash pH . . . if you add more calcium carbonate to compensate eventually you just end up with a chalky tasting beer.
I'm sure it was mentioned earlier that the best (not necessarily easiest) way to get a high alkalinity liquor using calcium carbonate required dissolving it in 'carbonic acid' under pressure