After reading up on how to dose CO2 according to pH and kH, I e-mailed the local water company asking for KH, GH, SO4, NO3, and PO4 in ppm. The director sent an email strait away as follows:

"The following data are composite values taken from recent finished water samples. They are good representations of the water delivered to our customers.

Sulfate: 75

Nitrate: 0.04

Calcium hardness, as Calcium Carbonate: 63.6

Total hardness, as Calcium Carbonate: 106

All units are mg/ L."

Forgive my ignorance here, but I assume "total hardness" is GH and "Calcium hardness, as calcium carbonate" is KH, correct?

Do we use -log(base 10) [x mg/L] formula to get GH and KH?

Was there a previous thread showing the ranges of "high", "medium", and "low" amounts of GH and KH?