homebrewer
Well-Known Member
My water quality report lists levels of calcium as Ca ion separately from hardness as CaCO3 and in a 1:4 ratio.
So does mine but in a ratio of 1:3. The best thing to do is call your local water plant and ask them specifically where that Ca is coming from. The vast majority of my Ca comes from calcium carbonate. There is a little that comes from the calcium chloride in road salt runoff but it's negligible.
Regardless of the Ca source, you want to work with near pure water and let your minerals come in a balanced form from your plant food.