I brought a kilo of Calcium Nitrate for my hydroponic setup.
The chemical formula for Calium Nitrate is Ca(NO3)2. I did a quick calculation of its weight:
Ca = 1*40.078
N = 2*14.006 = 28.012
O = 6*15.999 = 95.999
Total = 164.085
Hence the % in weight of calcium is ~24.42%.
BUT I see on the fertilizer pack that Calcium is only 18.8% and Nitrogen is 15.5%
Why is this?