Please Identify - Green Star Polyp Grey "stuff"

[patrsnracn]

This appeared a few weeks ago, just a little spot. This guy is

growing and way happy, so have not noticed a problem. Well tonight after lights out this is what we found, and the original little spot is now looks like a knob, upper left
It's like ash and blows (but not completely) off using just a stream of water from turkey baster. It is also now on the substrate @ ~ 1 O'clock

What is it and what might we do about it?
Please Help, any info appreciated

 

[Robink]

Not sure exactly what you're saying. Looks normal to me. Green star polyps retract at night. Just looks like it's growing. Mine covered a rock and then grew onto the back wall which is now covered with it.

 

[patrsnracn]

All the grey looking powder in the middle and then spread to the upper right and onto the substrate, its like dust or ash but does not wash away completely . Underneath the grey stuff is more colony, it is a round piece

 

[Robink]

Not sure what that is, looks like sand? Can you blow it off with a turkey baster?

 

[patrsnracn]

No, wont completely blow away, there is no sand in my tank, just CC, it is fungus like and spreading, like some kind of growth

 

[nervousmonkey]

Do you carbon dose? If you do, that stuff is probably bacteria that will go away on its own. They aren't dangerous as far as I know. I use biopellets on one system, and another that I don't dose carbon with. I get the same white fuzzy stuff on the bottom of my rock with the system that's carbon dosing and the one that I don't dose with a carbon has none of that stuff. Just a thought.

 

[patrsnracn]

no carbon at all?? Bacteria seems likely, I think we will just give it a nice bath in Revive tomorrow and see if it just cleans up??

 

[nervousmonkey]

Yeah I think it's bacterial. It looks and sounds like what I have, but I haven't ever tried to eradicate them unless they get too close to a coral, then I just bury the bottom of the rock in my sandbed and two weeks later the rock is clean.
Revive may kill em, I don't know. I don't think it will hurt unless you are pulling too much rock out and killing a bunch of stuff that will breakdown into ammonia and down the cycle, which you probably don't want. Try taking one rock out and try to get as much off the rock (in some salt water), then dip it if you have to.