Black algae?

[ccronje]

Hi all,

Can anyone perhaps identify this black algae that I have on my rocks?

Thank you

Chris

 

[Aiken Drum]

Are you sure its algae? Does it come off if you remove the piece of rock and use something like a toothbrush on it?

 

[ccronje]

Are you sure its algae? Does it come off if you remove the piece of rock and use something like a toothbrush on it?

I can't say for sure if it's algae, but it appear to be...saw a few spots here and there on the rocks and then it started spreading. Toothbrush helps, but due to the texture of the rock it is very difficult to get it off completely.