What are these?

[JFleur]

Seen these on my colony and im hoping they are not inhibiting growth..

 

[NS Mike D]

I had them with dinos, and I am not sure what they are, but I see air bubbles at the tips of some of them which send my dinos alarms off.

They are a PITA to remove, they anchor on the rock as if they were welded on and snap in half when you try to pulled them out.

I trust someone with definitive info will help out

 

[vetteguy53081]

Hydroids - manual removal with some tweezers or toothbrush will do the trick. You can reduce broadcast feeding which will starve them. I heard that boiling water via syringe works but we are dealing here with a cluster