I tried the water treatment calc with the example given on the Brupaks page but the figures for CRS come out quite different.
CaC03 is 195 p.p.m
target range of 30-50 p.p.m
to reduce the alkalinity by 160 p.p.m. CRS should be added at a rate of 0.87ml
So for 30 litres of liquor, 30 x 0.87 = 26ml
Put these same figures in the water treatment calc and I get 49.3ml