Help Identify what this is (bad or good??)

[LukeC]

These clear white tubes have been growing all over my rock work. I have tried looking up what they are and am just getting mixed answers.
Any idea? And if so, what can get rid of them(if anything eats them)

 

[DDenny]

Looks like a sponge of some sort I have some in my return in my AIO tank.

 

[LukeC]

Looks like a sponge of some sort I have some in my return in my AIO tank.

Know of any fish or inverts that would eat them?

 

[DDenny]

Know of any fish or inverts that would eat them?

They are harmless if it is a sponge of some sort and will usually disappear on their own.