What is it

[maxalmon]

What are these green hairy things? Incredibly small, almost invisible. The strand of chaeto kinda puts it into perspective.

 

[sassafrass]

They look like colonial hydriods to me , if so they are an invasive pest

 

[ngn8dogg]

aiptasia

 

[Misled]

<a href=showthread.php?s=&postid=13801609#post13801609 target=_blank>Originally posted</a> by sassafrass
They look like colonial hydriods to me , if so they are an invasive pest

X2, and yes they can be quite a nuisance.