when you were away did the tank get any light at all like through a window or it was dark all the time. a couple of more people had the same problem when they were away for a week and the lights were off. maybe all dark in the tank for a week could be the problemcarolines100;3394055; said:No he only started doing it after i returned from my holiday i add a friend feed my fish but told them not to turn lights on during the week i was away . So i thought he needed to get used to the lights again so i left the lights on but still no look so iam at a loss