Black Algae Question

[jtomasi]

So last night I decided to lower my purple haze monti because it looked like it was losing color. I got it a week ago and am still trying to find a good spot for it (Radion G2 it was about 5 inches from the light at 42%). Well I broke it clean off of the rock it came on and there was this black algae under it. Not cyno like where it went everywhere but tight to the rock. Wish I had a pic. Has anyone experienced black algae? It would be a huge pain in the A** to take the rock out of the tank and clean it off but if that is what I have to do so be it. My levels are all 0 and I might even need to start dosing amino and other stuff to bring P04 and N03 up/feed SPS.

I am afraid that the black algae is calcium based and will grow over my coralline. I am not to worried about it spreading if it needs No3 and Po4 as my cleanup crew will most likely take care of it way before it becoming a problem.

Any thoughts/Advice?

 

[blkhawk10]

I've had a black sponge before...could that be what it is? If it is I had two of em, one didn't really get that big and the other on the back of my tank grew like crazy and covered everything in its path.