Calcium Chloride
Calcium Chloride will help establish proper pH of the mash and wort, and provide sufficient calcium ions essential for enzyme function, kettle protein coagulation & yeast metabolism. Add if the water is low in chloride.
Brewing salts should be used sparingly to make up for gross deficiencies or overabundance of ions. The concentrations below are for 1 gram dissolved in 1 gallon (3.785 litres) of distilled water.
Dissolution of 1g of a salt in your water will result in a different value due to your water's specific mineral content and pH. However, the results should be reasonably close.
Concentration at 1g per 3.785L
72 ppm
Ca+2
127 ppm
Cl-1
Grams per level teaspoon - 3.4