ON John Palmer's How to Brew Nomagraph, there is a color bar at the top of the nomagraph.
a) What is the difference between the SRM numbers at the top and those at the bottom of the bar?
b) After drawing my line from Effective Hardness through Alkalinity to get a Residual Alkalinity... do I continue the vector of the line diagonally into the color bar? or do I go vertically from the Residual Alkalinity value.
Background for example.
Ca : 33, Mg 10, Alkalinity : 100
This gives Residual alkalinity of : ~60ppm
So if I continue the vector of the line, this gives good SRM values of 16 (on bottom) and 26 (on top).
If I go vertically up from the RA of 60, gives 10 (on bottom) and 16 (on top).
Which is right?