Beginning of coralline algae or something else?

[Nolanmf1209]

Hey guys so I just noticed this lime green algae one one my my pieces of live rock and I read that it could be the beginning of coralline algae so I’ll watch for color change but I’m worried that it could be something much less desirable. So what do you think?

 

[Nolanmf1209]

 

[moz71]

Hard to tell at this stage but it could very well be coralline. Should definitely know in about a week.

 

[reef lover]

The rock is maturing nicely...will be purple before you know it.