Low Light Coralline?

[Myka]

I thought so!! Thanks guys!

I've never been able to figure out why my tank doesn't grow coralline. I figured I could rule out lighting. The tank is 2 or 3 years old (can't remember), and there are only small patches of coralline. It's always been that way. It's an LPS reef, so obviously cal, alk, mag are all in check. I just can't figure it out...