|
Bear in mind that if all of the alkalinity in a salt mix (4 meq/L or 10 dKH) precipitated as calcium carbonate, the calcium would only drop by 80 ppm. Of course, that would leave no alkalinity, which was not observed. A drop of 1 meq/L (2.8 dKH) from normal is only a 20 ppm drop in calcium.
The caveat is that if you have not allowed the salt solution to totally settle, precipitated calcium carbonate could show up as alkalinity still, if the solids get into the alk test solution.
__________________
Randy Holmes-Farley
|