>Correct me if I >am wrong, but if you add only KNO3, aren't you adding K and N >in a 1:1 >molecular (not molecular weight) ratio? this is true. as it happens, KNO3 is about 40% K, 60% NO3 by weight so the ratio you're adding, as we measure it, is about 2 parts K to every 3 parts NO3. elie