Strange Glass Growth

[weirdedout]

Hey everyone,
We're a little new so we have no clue what is growing all over our tank glass. It's absolutley covered in it and popped up almost over night.
Any help is greatly appreciated as we are worried about what this is

 

[Geraud]

Colonial hydroids maybe? They have a stage in their life where they move around as medusae (like jelly-fish). So if you see these it is a tell-tale sign.

 

[duke62]

Slirorbid worms