Is this black normal

im not sure how to remove it, but i just wanted to point out that you may not be very okay with it being there when all of the adjacent rocks are covered. it would be better to take care of it sooner rather than later. im sure someone on here has an idea as to how it could be removed though.

 

to remove id probably have to frag about half of my zoas which im really afraid to frag, especially zoas after hearing what they can do, and thats the same area where my scallop/clam/oyster is on, and i want to keep that if i can