Bugs or ??

[swalke2]

Hi, I have a 20 water box build going on. Week 2 and going through the dirty stage. I have 15lbs of new rock and about a 1lb of rock seeded from another well established healthy tank.

I did a R/O top off this morning and everything looked as normal. Got home today and did a check and find that I have around 50 of these little bugs on my glass. They are about the size of a pencil lead, so hard to capture in a phot.

anyone have an idea of what this is?

Thanks for help identifying

 

[swalke2]

Figures I post and instantly identify them.
Hydroid Jellyfish

 

[Reefer-Madness]

You are right. They are a kind of hydroid. I’ve had them before and I think these are kind of common in newer set ups. Usually They will disappear as quickly as they appeared.