I have these all over my glass, what are they?

[Brandon M]

My tank is fairly new (~3 weeks) and I have these all over the glass. They are very very small. I'm assuming they are sponges but just wanted to make sure.

http://i161.photobucket.com/albums/t234/bkmicek/A.jpg

http://i161.photobucket.com/albums/t234/bkmicek/A1.jpg

[jbc123]

A type of hydroid from what I've read.

[Amazon4]

IME they show up for a while then gradually go away. I don't think there's anything that eats them. They shouldn't be any problem.

[mosssw]

Had them for about 3 weeks about the same time as you in the cycle. They went away and caused no harm. I had hundreds