You may have missed this bit:

> I have to add minerals to my hot tub to keep it in the appropriate range.

I don't know why, but too soft on a hot tub is as bad as too hard. When they installed it the tech tested and said "shit" and tossed another small batch of goop. Then he said "we get that a lot around here".

It's pretty soft. Colorado has a lot of different watersheds. We are St. Vrain with a little water from Thompson. But we are rarely above 60 ppm dissolved solids. It's a good thought, but I don't think my problem.