Apparently, it is difficult to separate out the Calcium from Magnesium hardness levels on the titration tests. I have purchased the Hach and Taylor tests and I think one other titration test for magnesium only. The hardness test should measure the combination of Calcium and Magnesium. The Calcium Test "should" measure just the calcium, and the Magnesium test should measure just the magnesium. I am not complaining about the tests these companies have made, as they do produce excellent tests kits in general. Anyway, I used all of the tests and could not reconcile the results. I ended up sending out a pool water sample to an agricultural analytical lab that uses something called Inductively Coupled Plasma Mass Spectroscopy. The results that I got back pretty much suggest to me that magnesium really interferes with the calcium titration test results. The calcium test seems to really show calcium plus a lot of the magnesium too. Since magnesium actually accounts for much of my hardness, it would be really great to have a reliable calcium-only test, as it it the calcium in water that really contributes to scaling. So, my question is, is there an inexpensive sort of test that can be used to get a good calcium test result at home?
Thanks in advance for any comments.