Just wanted to add that you can achieve the same results naturally. What Peter Eichler says is right on the money, "Just maintain alk, magnesium, and calcium and you'll have more coraline than you know what to do with." Just keep them stable and consistant. Knock on wood, my live rocks are encrusted solid with deep and bright purple pink coralline. Want to speed up the process, place some rocks in your refugium if it is lite 24/7. Your coralline will take off like you wouldn't believe.
Just my 2 cents.
Mucho Reef