So i have 7 tiger barbs in my 20 gallon they all seem fine except for one that tends to hang out behind the heater alone from the rest. He doesnt seem sick, his coloring isn't faded, and the water parameters are ok my ammonia levels are a little on the high side, but its nothing serious, and i am taking care of it. So is he sick, and he only does this durring certain times of the day, sometimes hes alone vertical, and other times he is fine and swimming with the group.