Why isn't my coraline algae growing!

[daniella3d]

My tank was healthy as can be with sps growing 1" per month and everhthing thriving, but I have near zero coraline algae..and I am extremely happy about it.

I keep my calcium at 420, mag at 1400 and alkalinity at 8. I dose trace element, amino acids and coral food...no coralline.

So the lack of coralline growth is not an indication of the tank being unhealthy. I noticed that some of my rocks have plenty of it and the majority of my rocks are totoka and that does not have a single bit of coralline on it. I guess the type of rock has a big influence.