They give 2.0 - 5.0% for potassium hydroxide, so 11.8 is approximate.
Also, there is no way my water and Your water to be the same pH and mineral content.
This spring, the water in the pipes moved from 6 pH to 10 pH. I am usually distilling water but sometimes I just use filtered tap water when I don't wanna wait for a few hours for the distiller to round up..

G