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Black Algae?

So after my battle with hair algae and two months of a nice clean tank. I just notice what appears to be black algae on a few of my rocks. IS there such a thing? Sorry I haven't had a chance test the params yet. I will in the morning. Just wanted to throw this out there. here is an iphone pic. Ill get a better shot tomorrow.IMG_0738.jpg
 

kschweer

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Are you taking about the rock or the sand on the lower left?
 

ecam

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I have that ony my rock too a red deep red or black. but it doesnet spread so i thought it was just a spoonge too.

Yes, I am talking about the black patches on the rock. Cyno? Not again. Crap.
 
Try and blow it off. If it come off easily then maybe cyano. If not then I would think sponge also.
 
Try and blow it off. If it come off easily then maybe cyano. If not then I would think sponge also.
I just did a water change. Phosphates and Nitrates were 0 prior to that. I tried to siphon some off but wouldn't budge. Its only on the rock closest to the bottom of the tank mostly where light is dim.
 
I tend to leave all sponges alone. I have black sponges in my tank too. Not the most sightly things but I've never noticed any harm from them
 
I tend to leave all sponges alone. I have black sponges in my tank too. Not the most sightly things but I've never noticed any harm from them
Do you think these are sponge? I just started to notice them this week. So I guess growth is still low.
 

TanksNStuff

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Looking at the new pics on my phone so although they are better I still can't tell for sure.

If it is a sponge "usually" they are good to have. Some are harmful but without a conclusive id we won't be sure. Most often they are good to have.

Could also be coralline algae which is also a good thing.
 
Looking at the new pics on my phone so although they are better I still can't tell for sure.

If it is a sponge "usually" they are good to have. Some are harmful but without a conclusive id we won't be sure. Most often they are good to have.

Could also be coralline algae which is also a good thing.
Lets hope its coralline. I didn't know it could be black. Let me know if you can get a conclusive identification after viewing on a computer screen. Thank you very much.
 
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