The best way to help your coraline grow, is your lights + keeping your calcium~400
I use B-ionic, i have some tuffa rock that i have used as "base rock" I can no longer tell the difference...well ok I can, but anyone else looking at my tank would not be able to...
its been about 4 months and ~ 80% covered in greenish coraline and 20% purple
i have 110W PC lighting on for 6 hours/day
goodluck!
-Oozy-