what's this?

[melanie]

I got a piece of live rock from my lfs and would like to know what these red hair-like things are. Thanks for any ideas or guesses.

[Rue]

...I have no idea...

But they look cool!

[coachfraley]

It's kind of hard to tell from the picture.

Maybe Halymenia or some other macroalgae?

[unleashed]

its either a juvenile macro algae or some kind of cyano bacteria

[kkyyllee]

its a type of macro developing, its not cyano, if you like it let it grow just not out of control

[mariusz621]

its a type of macro developing, its not cyano, if you like it let it grow just not out of control

Yes, it is sort of macro. It amy be difficult to get out of some corals when it gets between their branches. It can create like bush appearance oce established.