What is this? Good or Bad?

[Dastank]

I have something strange growing on one of my rocks. I have no idea what it is. It looks a lot like a bunch of small fans, but they dont retract. They are the brown colored bunch of stuff in the upper center of the picture. There pretty small still, just like the small bubble algae grown in the picture also. The have a stalk and fan at the top. Any ideas?

 

[Dastank]

I don't know what I was thinking when I wrote before.

they look like FEATHER DUSTER! Opps!!!!!

 

[iCam]

They look like hydroids.

If you can, try to remove them. Kalk and hot water never really worked for me, so I usually tried scraping them off as best as I could.

 

[techigirl78]

I have them, I agree, hydroids. I've been taking a pair of tweezers at the base (as close to the rock as possible) and pulling out the entire bunch. It seems to be working.

 

[Dastank]

Thanks for the info, I'll pluck them off!