good or bad

[jdckbr]

found these growing on a piece of old coral that was included with some live sand from the LFS to seed the tank about 6 weeks ago are these reef safe? Thanks

 

[Playa-1]

I believe they are harmless filter feeders, but I could be wrong.

 

[Capt_Cully]

Look like sponges to me. Harmless. I'd be more concerned about that leafy thingy. Looks like bryopsis algae. That stuff can be a real PITA in the first year or so, while the tank stabilizes.

 

[Aquarist007]

I agree--sponges

regarding the possible hair algae--can you take another pic of that rock

 

[jdckbr]

thanks everybody, the new lawnmower is mowin the stuff down,man that is one fat blennie hope he dont pop...