Hydroids on glass harmful?

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

Fish-guy

Aquarium Advice Freak
Joined
Oct 15, 2011
Messages
270
Location
Canada
I've got lots of these little star like things on my glass. I think they are called Hydroids. Are they harmful?
 

Attachments

  • image-3567466023.jpg
    image-3567466023.jpg
    61.5 KB · Views: 210
Back
Top Bottom