When I got up today I did my usual checkin of all the fish, turning on lights and whatnot. In my qt tank I noticed I was missing a cardinal tetra. I found him wedged between my heater and the glass. Thinking he was dead I pried the heater away and he sank to the bottom. As I turned to get the net, he must have started swimming again. Not dead after all! He was at the surface for a bit then went back to his school. I had noticed he had a dent in his side, but it doesn't show in the pics very well. Is there anything I should do for him? He is swimming fine now, but I would like to head off any potential problems.