One of my 12 angels in my 100 gallon tank has recently been acting lethargic. The last couple of days hes been hanging out toward the bottom and not really eating. And then last night he started to lay on his side on the bottom. There are no evident signs of trauma or disease on his body. He is breathing a little heavy. I just dont know what is wrong or what to do about it. I dont know if its worth taking him out of the tank and into a hospital tank but I wouldnt know what to treat him with. Please anyone help me. Thanks!