Need Help Identifying - What is this?

[newreefer]

Have just completed week three of cycling my first nano tank. While checking out the progress and the huge pod population crawling all over the inside front glass, I noticed 9-10 of these attached to glass.

They are "hairy" and very small - center/base size of pen tip. They are fairly flat on glass and the arms don't appear to wave in current.

Are they baby glass anemones (aitpasia)? If so, how do I get rid of them? Have a Peppermint Shrimp, but not sure he could/would go there. They appear too small to inject.

Any help in identifying and, if necessary, eradicating appreciated. :help:

 

[newreefer]

Or are they hydroid jellyfish? Are these harmless?

 

[TropicalNorth]

Hydroids.
I had a few in my tank, just like that, when it was about 3 months old but they all just went away within the week. I've read they can get out of control but usually they just go away. Just keep an eye on them.

 

[fsn77]

They typically exhaust their food source rather quickly and disappear within a month or so.

 

[newreefer]

Thanks for confirming my identification. Glad to know they are harmless, but will keep a close eye on their population. When I clean my front glass, I think I'll wipe out most of the current population.