Help With ID

[jarret]

I work at a local pet store and we have 2 reef tanks setup. In one of the reef tanks we have a blue algae/coral? growing and have no idea where it came from. I'm attaching a pic below and hopefully somebody on here will know what it is.

Is this harmful to the tank at all? It seems to have started in the back right corner and is spreading its way throughout the tank.

 

[likestofish]

looks like a sponge

 

[Myteemouse]

+1 on sponge
They grow in all colors and shapes..

 

[barrakooda]

Looks like a sponge too.
Not harmful to reef aquariums... but some fish do eat sponges like angels and triggers. If you are going to transfer the sponge, do not let it get expose to air because as soon as they touch air, they die. Bag it in the water. =)

 

[jarret]

+1 on sponge
They grow in all colors and shapes..

Ah ok, wasn't sure if it had a particular name or not....

Thanks for all the answers.