Is this growth ok in my reef tank?
 

I have had this black pinnacled velvetey type growth for the past few months on some of my live rock. I did ask about it before, but was unsure of the responses.

Anyway, it is about the size of a loonie and I would like to know if I should leave it, remove it or love it?

Please advise.

Cool, What is it?

I will bump this post. Interested to know what it is as well. Anyone?

interesting could be some sort of spunge or leather finger coral.

Bill

Huh. Pretty strange growth... you mentioned that it is velvety, do you mean visually or to the touch? How tough is it, can you just pull a chunk off or is it strong? Is it soft or hard, like does it move in the current?

i had gotten a piece of this on some live rock that i had picked up. i thought it was a piece of rubber or plastic (as thats what it felt like, really smooth and a bit bendy) then i thought it was some kind of sponge, i still have no idea what it was.

it was removed from the rock and disposed of.

I have no idea what this stuff is, but I had a piece of LR that had some of this stuff, but dead. Interesting to see it alive. If it is the same thing, it was so difficult to remove when dead, that I didn't bother.

how does it respond to iight and flow?

Is it growing like towards the light or trying to get away?

Looks like its exhibiting some sort of photo tropism so I would lean away from it being a sponge. What ever it is it looks pretty cool, my guess is some sort of calcareous algae. Anything in your tank go after it as a meal?
Levi

(Only thing is its black, and you don't see to many things that use photosynthesis that exhibit an overall black pigment.)

It is velvet to the touch, is rigid enough that flow does sway it.....
 

and grows straight up as if reaching for my HO T5's. None of my fish touch it and have an Algae Blenny, Yellow Tang, Chromis's and godby with cleaner shrimps.

Not sure if I love it or hate it.....lol


Note: should read "flow does NOT sway it"