I also have a Valentini, with a tank raised Maroon Clown. The Clown has been in the tank the longest, and the Puffer was last introduced. My Clown has also been nipped at by the Puffer, usually on the tail, but I have also seen little nip marks on his dorsal fin and even the pelvic fins. I've actually caught the Puffer trying to do it, and I've yelled at him, signaling him to go to the other side of the tank, which he does. It usually takes anywhere from about 7 to 14 days for the fins to grow back and look normal. It seems like my Puffer will do this to the Clown atleast once a month now, used to be a few times. But it seems to be getting less frequent (knock on wood). I also have a Fuzzy Dwarf, and the Puffer wont go anywhere near his fins lol. Feed your Puffer a mussel once or twice every few weeks
