What is this?

[ReefGazer]

I have no idea what these are. They are quite small and brown in color. Any ideas?

 

[tdileo]

I believe it’s some species of clavularia. It’s a fast growing soft coral, some consider them invasive.

 

[o2manyfish]

Yes Clavularia, If you can limit their growth to back wall of the tank, or a specific rock these are excellent filter feeders.

They are also much easier to remove than Xenia. These grow as a thick skin patch. Put your fingernail under the edge of the colony and you can peel it off any surface to keep it in check quite easily. The more light they get the darker the color. Inside my display tank my Clavularia are a pretty bright white/silver. Outside in the sunlit tanks they look similar to the ones in your photo.

Dave B

 

[ReefGazer]

Bingo! They are prolific and seem to spread pretty easily. Thanks guys.

 

[Clueless Reefer]

If your not a fan of them and are wanting to control them you could attempt to use Joe's Juice on each polyp and see if that knocks them out.