Gonna be hard to tell with the picture extremely dark in blue lighting. Typically will be sponge but need pics under white lighting to confirm.Hey guys, been a while. My buddy got into reefing recently and this black stuff is starting to cover his rocks. Not sure if its a sponge or anything he should be worried about. If anyone can identify this and let me know on how to remove it, I'd appreciate it immensely.
Yes and does look like undesired black sponge. You will need to pull rock (I know) and place in a container of tank water and scrub off with a firm toothbrush or automotive detail brush and 3% peroxide. This type of sponge has low level toxins.Hope this is a little better.
