Growth on LR in FOWLR

[swordstool]

I'm a newbie, so excuse me if this is common, but what is this? It's all over one piece of LR from my LFS. Started as just purple dome, then the branches slowly came out over the past 2 weeks. It doesn't seem like it has spread to other rock yet.

 

[daney90]

Not sure what that is. I'm a newbie too do you know what is this brownish green colouration on my rocks? Is that coraline algae?

 

[swordstool]

Looks like bad algae, not coralline.

 

[daney90]

Looks like bad algae, not coralline.

Cool.. Thanks