Gray fine dust in tank

[Mill]

Hi, does anyone know what this fine gray dust is? I’ve been trying to figure out where it’s coming from. First thought was from a rock.. only thing running on this tank is carbon and the carbon dose tumble a bit in the reactor.
Any help is much appreciated!

 

[Budget_Reef]

Did you have anything else in the tank or just rocks

 

[Chris A.]

If the rocks were from someone else’s tank they could be loaded up with ditrus and that’s what your seeing.also carbon should never tumble only gfo. Carbon will breakdown really fast tumbling

 

[gobyvin]

I got some free rock and it was LOADED with detritus. After months of curing , scrubbing and 100% water changes it still had some. 1 year later, almost gone. This was after laying fallow in the dark too!

 

[gobyvin]

It is good now though! Just need the Rona to go away so I can get my tank back. It is holding my wife’s school reef now...

 

[afboundguy]

My first thought from reading the post without even seeing the pictures was detritus from the rocks as well...

 

[Mill]

Did you have anything else in the tank or just rocks

Just some corals and some clownfish.