unless you have already pre-mixed it under the guidelines of Randy's two-part :-)
http://reefkeeping.com/issues/2006-02/rhf/index.php#4
well, it is still dow flake but if you premix it the calculations for dosing changes, and you'd pick "Randy's Two Part" in the list. I suppose that's not exactly what you asked but I figured I'd chime in since I was right in the middle of mixing a batch of the exact same stuff and was wondering what brand of calcium it was myself :-)