Are these hydroids

[PR_nano]

Found this small patch in the back of the rocks, wondering if it is hyroids or some type of duster.

Can take additional pictures with more white.

 

[Nburg's Reef]

Its hard to tell for sure from the washed out picture, but looks like it. I would try to kill them asap.

 

[PR_nano]

Thanks, would a toothbrush work or are they like Aiptasia and will spread if irritated?

 

[Nburg's Reef]

I’m not sure exactly, but I know they can be difficult to control. I had a rock that was really covered so I just tossed it before it could spread. Now if I see some, I just put super glue on them.

I would not take the chance to scrub them.

If I recall correctly, there are in tank treatments but it’s risky.