I have just inherited a clown fish (you know the one like NEMO). I'm certain he's not acting right. He seems healthy but he hangs out at the top corner of the tank and is constantly swimming with his nose in the glass corner. Its as if his swim bladder won't empty to allow him to adjust his bouyancy. He can force himself down to chase food but otherwise can't stay down. His tank mates are : 1 hippo tang, 1 yellow tang, 1 damsel, 1 fire angel. They all leave him alone. All the tank mates seem very healthy, I've tested the nitrates, nitrites, ammonia, pH, salinity. The water looks great. SO, what's wrong with my clown?