If I put in a now FC value and a target FC value it gives me the answer but when I come back it reverts to the same thing I had before and does not remain the same. The now and target values do not remain the same. For me, they always go back to 4 ppm.
I have some 1 lb bags of Cal Hypo that say Calcium Hypochlorite 52% but there is not a selection for that. The nearest selection is 53%.