I ordered the exact bulb from Melevs reef. Mine did not grow at all in the DT with the normal lights. It has taken off like crazy with the 5100k bulb. What are your nitrates? Nitrate is fertilizer and plants need it to grow. I don't know about the turning white thing, but if it's not growing for a lack of nitrates and phosphates it's probably a good thing. It shouldn't be dying though that's weird.