Is this stuff bad?

So I have a few rocks left in my fuge. One of them has these red things growing out of it. I mean, it looks pretty cool and sort of like a coral or a sponge, but I have no idea what it is. Is it something that can spread and take over, some kind of algae? Harmless? Should I leave it in my sump, or maybe can I place it in the display?

Maybe someone can help with telling me what it is.

 

looks like some kind of red macroalgae to me but i'm not 100% sure on that. I would say as long as it doesn't overtake your fuge then leave it there for natural filtration.

 

You've pointed me in the right direction. I searched for red macro algae and eventually stumbled upon Nemastoma. If thats what it is, this is a nice score. I've read about people keeping it in the display and that it glows under actinics. Although I'll keep it in my sump.

 

You can PM John Maloney and he should be able to ID it.

 

red gelatinous algae are generally good guys. I have that plant in ID guide but it escapes me now...I have kept it before too. It looks like a Sciania, Nemastoma relation in the Nemastomacae super family if you try to look through algae base.