My Blue Hippo Tang has been losing too much weight in the past 6 months. I've had him for 6 years and he's always been a happy fish, even now he still is. Luckily he still comes out during feeding and when I put my face to the tank but he's resting in the rocks more and more every day. His ribs are showing and he's looking way too skinny. No signs really of Ick or any other disease. I've looked at other forums and I didn't see any suggestions that I'm not already doing but figured I'd post here just in case. 4 months ago I upped the feeding to twice a day. He eats but he's not as aggressive as he used to be. He seems to be getting worse at identifying and eating food, but he still gobbles up a good amount. I give Nori once a day on a clip. My Sailfin Tang gets most of it, but he still tries and gets some. I soak food/ nori in Selcon every two or three days. I alternate frozen Brine / Mysis shrimp for main food.