The iDip app lets you set defaults for units. This is an area I'm not sure I have correct in order to use the numbers with Bru'n Water.
Here's how I have mine set:
Total Alkalinity, ppm as CaCO3
Calcium, ppm as CaCO3 (I just noticed this is wrong, should be ppm as Ca)
Chloride, ppm as Cl-
Total...