What Erik said.
Keep in mind that water analysis are often (usually) reported as CaCO3 equivalents. That is, calcium may be reported as CaCO3 even if the calcium is not in the form of that salt. Calcium can be associated with sulfate for example, but be reported as the CaCO3 equivalent. To fully understand the water, you need to have a complete water analysis done. This will have all anions and cations reported and will give likely associated compounds. You need to know if the sample is reported as ion or as CaCO3 equivalent to balance the equations if this is not done.
Mike

Mike