gray matter or ......?

[lilreefer1975]

I have seen on many occasions this gray matter in different spots of my tank.
I've actually saw it coming out of a rock with some zoas on it being pushed out like waste
What is this stuff? And more importantly what is making it?

 

[Julio]

pics please?

 

[JCTewks]

ounds like poop to me...ther are all sorts of small critters that live in your rock, they all eat, and poop.

 

[seastar12]

Pictures would help, it might just be waste, though.

 

[Youngsilver]

depending on your definition of gray, it could something like a limpet spawning, I have watched very small (penny sized) plumes of what was noticably eggs, and plumes of a white/grayish substance that I eventually realized was coming from 5 very well camoflauged limpets.

But without a really good pic, it really could be about anything