What are these?

[reefertank]

I bought some live rock and found a few of these, some are green and some black with red tips.

 

[TheAquarian]

Looks like a majano anemone

 

[reefertank]

Looks like a majano anemone

Good or bad?

 

[rkpetersen]

They're pests. Like aiptasia, they can multiply very quickly, and if you try to remove them, fragments that are left behind or get into the water can form new ones. People inject them with a variety of things, or feed them stuff like Joe's Juice, to kill them.

 

[NY_Caveman]

+1 on Majano. Definitely a pest.

 

[reefertank]

They're pests. Like aiptasia, they can multiply very quickly, and if you try to remove them, fragments that are left behind or get into the water can form new ones. People inject them with a variety of things, or feed them stuff like Joe's Juice, to kill them.

Ok I didn't see them on the rock when I put it in my tank. They are not getting lights and shriveling up. So I will let them die