Originally Posted by ajdelange
Nothing wrong with the calcium or magnesium at respectively 21.5 and 17.5 mg/L as the ions. But 44 ppm alkalinity isn't enough to balance this profile. You'd need more like 95 for that (or more sulfate or chloride). In addition to that the molar ratio of carbonate to bicarbonate in the report is (24/61)/(42/60) = 0.562 which corresponds to a pH of 10.125 so there is something fishy there too.
OTOH pH 9.6 is by itself high. Above WHO recommendations and a full pH above the saturation pH even when calculated with the 44 alkalinity level. Aren't your guys worried about occlusion?
As for the ratio of carb to bicarb, I may have not listed values from the same day and I definitely just threw in our average pH which could have been different at the time of the listed samples. I'm not looking for exact numbers because we have some fluctuations from day to day and most certainly from season to season being a surface water plant with 3 different sources which we use independently or vary the blends depending on source quality.
Our primary reason for the higher pH is lead and copper compliance. Because we had some homes fail tests many years ago, we were required to provide additional protection. To achieve and maintain this protection, our operating permit requires that we provide a minimum CaCO3 precipitation potential (CCPP) of 7.5 mg/l. At our target pH of 9.5 we generally average a CCPP of 15 mg/l. Lowering the pH would reduce the CCPP. That would reduce scale formation but at some risk of again exceeding SDWA lead copper standards. We have seen good results with this configuration and have been using this protocol now years.
I entered my information into Kai's spreadsheet and I thought it looked pretty decent? I'm showing a residual alkalinity of 18 ppm which doesn't seem terrible to me but perhaps I'm underestimating the importance of a complete ion balance (mine was 9.9%).
I then entered some info from my last recipe to predict mash pH and it came out to 5.56, a little high but not far off right? This recipe wasn't a huge grain bill either IMO...8 lbs two row, 2 lbs Vienna, 0.5 lbs crystal 10L. So I guess I'm thinking things aren't all that bad but perhaps I will borrow a portable pH meter from work and take the guesswork out of it altogether.