Not Padina then...maybe it is a type of coralline. Never seen it before though. :D

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I really don't think its coraline, I had something very similar grow on one of my zoa colonies. Its a little more fleshly than coraline and it grows a plate right over the polyp killing it. It's sweet looking just watch out I know the stuff I had grew fast and was a PITA to remove.
Levi

It is a type of macro algae. Not sure of the name thou. It is nice but can take over your tank. I just pulled a bunch out of my nano.

Gah how do you delete posts?

http://oceanaquatics.com/store/produ...t-Plate-Algae/

Peysonnelia spp? Not sure what the texture of this stuff is, but it reminds me of the stuff you have.