Did you make your own, with baking soda, ice melter and epsom salts? :)
I used to use that in NY, when I had a larger tank with hard corals, and never had any problems. I would also dose daily with pickling lime, which is a good kalkwasser substitute.
Currenty, I don't use the 2-part, but intermittently add the settled pickling lime water to boost calcium.
I have not dosed my tank in the past, but just realized both my Alk and Ca are quite low (probly because of consumption by very large monti caps in my 28g tank). I just started dosing randy's 2 part DIY recipe and it seems to be working out pretty well. has anyone else here used this recipe? Anyone run into problems with prolonged use?