I have just purchased a 6" Fahaka Puffer and he stays in one spot most of the day, he has been in the tank since last Friday morning. He eats the marble crags that I feed him however that's the only time he swims is to eat. Then he goes right back to the bottom of the tank and he just sits there. He shows no interest in swimming around ever. He is in a 100 gallon tank and the filtration is extremely over board so it can't be bad water quality, plus I checked that already. Another thing is that he seems to be breathing heavy is this normal? I really need some help and advice, because I have seen other Fahakas to swim all day long and stay active