After reviewing a water profile created by a brewer using Palmer's Spreadsheet, I found a very serious error that must be corrected.
The bicarbonate concentration calculated from the addition of chalk is in error. It appears that the calculation is actually giving the carbonate concentration instead of the bicarbonate concentration. Since carbonate cannot exist at typical mash pH, it must be converted to the bicarbonate form. That means that the carbonate concentration should be multiplied by 2.033. This also means that the alkalinity calculated for the chalk in the spreadsheet is also in error and should be multiplied by 2.033.
Another significant error in the spreadsheet is the residual alkalinity that the spreadsheet recommends based on the beer color. It is far too aggressive and recommends far too high a RA value to the brewer. There are no water profiles from the historic brewing centers with a RA higher than about 180. This spreadsheet will frequently point a brewer to recommended RA values of 300 to 400. That is extremely excessive and leads to soda water beers. A more appropriate correlation between RA and SRM is as follows: RA = SRM x 4.5. And given that correlation, the maximum RA a brewer should ever use is about 200.
Until the revised spreadsheet is issued, I recommend that brewers refrain from using this program.