Can anyone tell me what this is?

[rynosaurus]

This aquarium is at my training center, not my tank. However this white fuzzy stuff is all over and my curiosity must know. WHAT IS THIS STUFF.
Tank has only three large fish and nothing more.
can anyone ID this for me.

 

[Cell]

Colonial hydroids?

 

[Sharkbait19]

Looks like hydroids

 

[rynosaurus]

Awesome! Time to do some research and see what I can learn. Thank you!