Blackk stuff?

[cash1103]

I have some thick black stuff starting to grow in patches on my live rock. Does anyone know what is is and what to do about it? Thanks

 

[dogstar]

Hard to say by your discription or without a picture but if I had to guess I would say some type of sponge.

 

[nytrillium]

is it growing or was it die off from when you got the rock. I had black stuff on some live rock that was shipped to me and it was die off. Eventually it will get broken down in your tank.

 

[cash1103]

It's a thick, almost shiny black substance that is growing in patches about the size of a quarter. I can pull the whole patch off with my fingers. It started in one or two places but now seems to be showing up on several other rocks.
My tank has been up for more than a year
I've tried to create a link below to a pic:
Pic

 

[nytrillium]

Hmm, I really cant help you then. It may be a bacteria type stuff like cyano maybe? Or maybe an algae of some type.

 

[georgene]

Originally Posted by Cash1103
It's a thick, almost shiny black substance that is growing in patches about the size of a quarter. I can pull the whole patch off with my fingers. It started in one or two places but now seems to be showing up on several other rocks.
My tank has been up for more than a year
I've tried to create a link below to a pic:
Pic

It looks like some kind of oil slick to me. I think it could be some kind of sponge. I had a gray sponge in my tank; it was killing some of my coral. It picked off really easy. I think if it were in my tank I would get rid of it.