Thanks for the advice. I'm upping the supplement of nori. Wasn't sure if they were just grazing that well my main concern is my new purple tang. It settled in dominance wise and is swimming with the other tangs but is looking overly skinny while rest is fat. I had hoped a new grazing rock would help until he gets with the program. I noticed it today and have been feeding extra beyond the automatic feeder to make sure he gets something in him. Currently have nori hung up to possibly promote more grazing. And at this point I probably should have the thread moved to a different section.