Hydroids or Aiptasia?

[steph]

I have what I thought was aiptasia growing on a rock. Now, I am not so sure as they seem to look a bit like colonial hydroids. They appear to be green (almost lime green) and have stayed about the size of a pinhead for over a month.
Can someone confirm what these are?

thank you!!

 

[Niagarafirecorals]

Hydroids

 

[steph]

Thank you!

 

[Luigi]

I second that