calcium chloride and gypsum are the two key things to have..... However, for an ESB, gypsum is more important than Calcium chloride. I am not familiar with calcium carbonate.... so hopefully someone else will pipe in on that.
One thing you could do is to use 1 gram of gypsum per gallon of mash water and .2 grams canning salt per gallon of mash water (same for sparge water on both). That would get you close on your calcium, sulfate and chloride.... assuming youa re using 100% RO water. I ran those through Bru'n Water with 100% RO water. Not perfect, but should get you a solid water profile for an ESB.
Maybe others have some better thoughts?
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