Hydroids or something else?

[LeopardWolf]

My tank is a little over a month old. Over the past few days I noticed something against my coralline plate and thought it was a random strand of dog or cat fur or mucus from the vermetid snails which happen to stick there. While I was looking around and cleaning last night, I noticed it seemed as if there was more of the stuff, like it had grown.

Concerned with what it might be, I grabbed my macro lens and tried to get some halfway decent images. The stuff is tiny, thin and pale colored, which made it a real pain to get enough detail, but hope someone can help me figure out what this stuff is.

It forms like little branches and some areas have "buds" with little "arms" ending in tiny dots.

Whatever it is, it's alive. I watched it through a magnifying glass and some of it twitched a little and moved slightly.

My first thought was immature hydroids or something similar. They are super tiny, less than 0.5mm and the dots may be smaller than a period mark.

 

 

I am hoping I am wrong, because I have tried to be very careful about adding things to my tank, treating the rock in coral dip and even hyper-salting a few (this all done in a quarantine container after I had removed anything beneficial I wanted to keep) pieces before I added them to my tank.

I guess there is a slim chance they could have come from the live pod cultures I added if they were in free floating form with the pods or something.

I left the images large to show detail, apologies if that causes anyone problems viewing.

[arwndsh]

Not all hydroids are bad just as an FYI.

 

But it looks like its just algea of some sort to me. Can you get a less close up picture?

[amphipod]

Not all hydroids are harmful, yours are hydroids also