My clown trigger is by himself in a 75 gal, for three years now. Since I last changed the water he's been a real picky eater. He stopped eating krill and would only eat formula one for a week or two. Now he doesn't seem to be eating at all. The weird thing is that he acts like he is hungry and will come to the top like he's ready to grab the food but when I put it in, either he backs away from it or he literally tries to grab it but it's like he's not seeing it properly and keeps missing it and gives up. I've tried krill, large shrimp, formula 1, plankton cubes, clams on a half shell. I had the water tested and they said it was ok.