My violet goby stopped eating like his regular vacuum self about a week ago. Now it looks like he is wasting away. He is even tipping over on his side. He is about 8-10 inches in length and up to this point in good health. The only idea that I have is that maybe he has a gut impaction due to me being stupid and listening to the chick at the fish store when she told me to put hermit crab sand in with the small pebbles so that he and his tank mates could dig easier. Now he is very skinny except a bulge right before his underbelly fin starts. Any ideas? I have done water changes. He had been eating frozen blood worms, frozen brine shrimp, and tropical and gold fish flake food. Granted I have only had him for two months but before now he would eat everything you put in the tank within a few minutes.