what is this??

[newtoreef]

what kind of algae is that? is it a bad one? what should I do? help??

[jimlin]

hydroids?

[Marc Weaver]

Yep, looks like colonial hydroids (google it and check the first few images.) Read up on killing them. Some say they are difficult to get rid of, some say they go away by themselves. If I were you and they are only one one small rock, I'd take it out and discard it to be safe. Some people even use a blowtorch to burn them off. I've never personally had to deal with them, though.

Edited September 25, 2012 by Marc Weaver

[Coral Hind]

I agree with Marc, I would try to remove or kill them. If they are only on the one rock and it isn't really big then I would remove the rock and let it dry out to kill them. Then return the rock back to the tank to color up again.

[newtoreef]

great guys thank you so much. I will removed this rock and let it dry. Could I put on some kind of solution to accelerate the process??

[Coral Hind]

If you want to use a solution you could use an oxidizer like a bleach and water mixture and soak it in that for a day. This will kill anything on/in the rock and also dissolve the organic matter. Give it a good rinse and return it to the tank. The bleach will break down by the next day into harmless water and salt. Placing it in the sun and open to air exchange will speed up the breakdown of the bleach.

[newtoreef]

will do . thanks Coral Hind!

[treesprite]

Polyp stage of jelly fish nausithoe.

http://www.masa.asn.au/masawiki/index.php/Nausithoe

Edited September 26, 2012 by treesprite