GFO turned Grey????

[bsr2430]

Can anyone answer this?
My GFO turn Grey?
it was also hard as a rock, it was tumbling last I checked.
the top of the insert of the reactor was white too. Very weird!
Anyone help explain this?
Couldn’t find anything about it online.

 

[bsr2430]

Come on ladies and gents.
Will also say, in the insert at the top, it looked like cobwebs, but it was just a white coating of something?