What is this ?

[tharkema]

Been almost 3 years since this post was touched... but I have the exact same stuff that I have been trying to get rid of for 1+ year. I had a blue tuxedo urchin, but he would just eat around it. I heard a Naso Tang might do the trick but my tank is not big enough to support it (60g).

I have been putting 2-3 pieces of live rock in my sump and waiting about 4+ months for the stuff to disappear. However after switching cleared up pieces with stuff in display tank it eventually comes back.

Anyways any suggestions would be greatly appreciated. I have been peeling off what I can... but need to get rid of this stuff