Choosing an Alk/Ca Additive
•Kalkwasser
–Ca(OH)2 = Ca++ + 2OH-
–OH-  + CO2 = HCO3-
–OH-  + HCO3 = CO3—
–
•Vinegar (acetic acid) can be mixed with the kalkwasser to both increase the potency and decrease the pH.
•Cheap food grade lime (pickling lime).