Make sure your bottled water is distilled, and that you have your calmag, rather than water bottled for drinking, in which case it doesn't have to conform to any specific conductivity standards and can have dissolved metals in it.
Damn your tap water is atrocious. You live in a SuperFund site or summin? Dag, yo. Can you even SHOWER in that or does it come out of the tap in a slurry?