are they colonial hydroids or tiny feather duster cluster? *cranberry?

[lauremf2002]

Ok, I just looked at Cranberry's work in progress hitch hiker page and what she pictured as colonial hydroids looks an awful lot like something I have in my tank that I thought were tiny feather dusters. They are so small that they dont come out in photos. What are some ways that I can discern the difference, and if they are colonial hydroids, are they bad and why? Could I put them in my fuge or will they spread?

 

[cranberry]

If it's hydroids, they will spread. BUT, I've personally never gotten rid of any of mine and they haven't gone anywhere.... but I was aware that they could... they just never did.

 

[lauremf2002]

Hmm... I really kind of like them and they are on a very small rock that I have by itself on the sand. they have been there a month and not spread so, Ill just leave them. But I will keep an eye out and if they do start to spread Ill just remove them. Thanks for the reply