Grape Calupera is also known to go asexual and blow spawn eggs or sperm or whatever :? all over your tank, people who do grow it on purpose do so with 24hr lighting to keep that from happening. I had some of that stuff in my sump when I first started up.. the bigger leaved other kinda of calupera took over and choked that grape one out. i'd move it to your refugium if you have one and grow some for that new tang your planning on picking up, like everyone said Tangs LOVE that stuff.. for me way more than nori, my angels and foxface gobbled it up like candy also.