If he's swimming up to you he may be hungry....they start realizing where the food comes from quickly, you should start getting in the habit of shaking your hand or showing him the food before you throw it in and guide him up to the corner, always throw the food in the same spot. I would say don't feed him for a whole day and then the next night then try that. He should go right for it. I would stay away from the powerhead for now but I would get some more air in there. You have the temp high, leave it there that's good, and throw in a little salt.