Algae ID?

[sandswhitson]

Can anyone ID this for me. I don't believe it is Cyano it is black in color and most of it doesn't have the bubbles that Cyano usually has, although some chunks of it does have bubbles. This tank has been setup for around 4 years without a change in feeding or husbandry. Any thoughts?

 

[ac7av]

Most likely it is cyano. I’ve seen it in many different colors between green and dark purple. Judging by the way it looks if it’s the consistency of cyano it’s probably cyano.

 

[sandswhitson]

Isn't cyano usually slimy? If I pull this stuff off it comes off in big chunks like hair algae.

 

[ac7av]

Do you think it could be sponge? I’ve had some dark color ones but never grew very fast.

 

[reef18ster]

+1 on sponge.

 

[NC2WA]

I've seen cyano in big chunks before, I don't beleive it is a sponge.

 

[dtd87]

I have cyano, someone get rid of it for me

 

[returnofsid]

I believe it's probably Cyano. However, look closely for any "openings," like those you've seen on more common sponges. Feeling it, does it feel like it could be a sponge? If so, and if it's black, there are a lot of black sponges and while most of them are fine, there are a couple types of black sponge that's known to kill corals, mainly Zoanthids.

 

[jill]

I believe it's probably Cyano. However, look closely for any "openings," like those you've seen on more common sponges. Feeling it, does it feel like it could be a sponge? If so, and if it's black, there are a lot of black sponges and while most of them are fine, there are a couple types of black sponge that's known to kill corals, mainly Zoanthids.

It looks kind of like a black sponge that I have.
So Sid, my sponge is slow growing - should I take it out or just wait and see if it starts to grow towards my zoas?