will only affect the Ca
levels. I would use caution buying soomething like that off the shelf as many are not suffieciently pure.
Calcium hydroxide (limewater) raises both alkalinity and Ca
equally. There are many types of pickling lime available Ball's and Mrs. Wges being two of the more popular. Due to the high pH, the purity is less important as many impurities will precipitate out. Try asking for the brands mentioned, mabye you'll have better luck.