What type of algae is this?

[EeyoreIsMySpiritAnimal]

I was looking at an urchin.

Urchins will eat coralline algae and most prefer this to the other algaes... Coralline algae on your rocks will discourage other types of algae growth. Unless you're sure you don't want any coralline, I'd vote against an urchin at this point (if an urchin is a "must have" critter for you, fine, but for now, at this stage of the game, be patient, let the algaes come and go as I described before, and go with a cuc that includes several types of snails!)