Yesterday I came home from work and went to feed my fish as i do every morning when I get home from work and I noticed a lot of his tail fin is just missing. It looks tattered but there are no spots and no red at all and no fish with him. He seems to also be trying to rub against the side of his tank. Today this is a small hole in his top fin in the middle. I have no idea what is going on. I read that the special type of salt for fish is good and put it in for illness but I'm not sure its enough and at the rate its dissolving i'm worried that if I'm not doing the right thing he isn't going to be able to swim. :-( He is in a 5g tank, filtered, heater to 78degrees. The water is testing fine. I don't know what to do/get to make him better. Please help. I will try to get a good picture. He has one live plant and one fake I don't think they are the problem because they passed the stocking test and it literally happened overnight. I stare at him all the time and he was fine until I got home from work. He is still eating but sort of seems panicked now. I don't know if i should unplug the filter (its baffled) or not since he may start having swimming issues? He also has this one spot on his head. I will try to get a pic to load but he is swimming around a lot so I'm not sure I can capture the detail.