hello i recently bought a yellow tang and a percula clown fish. the tang was supposed to eat green hair algea and although i don't see any difference yet i do notice that he is lightening in color (turning white in spots) the top of his head and the bottom of him and a small section along his sides. i was told that this is caused by not enough algea for him to eat but i assure you there is plenty. i have cut back my lighting to only 4-6 hours max a day to reduce the growth of the hair algea (red and green). i have seen ick before and am 98% positive this is not the case. any help would be greatly appreciated.