is this stuff rare?

i have had this brown stuff growing in my reef for months now. it is fairly quick growing, and looks almost like coralline algae forming round plates, however it is soft and spongy to the touch. i have been at a loss with id it, but i just finally saw it on google. it is called brown bracket seaweed. i have never seen it in any one elses tank. anybody know about this stuff? it just popped up in my tank haha.

 

Maybe Padina sp. "scroll algae"?

 

Yep. Lobophora. If it just one rock growing it take it out and quarantine until you have it controlled. Standard CUC, emeralds and Lettuce Nudi's won't eliminate it but may eat enough to keep it under control.

 

its extremely easy to control. it peels right off the glass and rock. its pretty neat actually i keep a little patch of it on the back glass

 

I had it become a royal pain in my old 180. Get it out.