Green barb scales missing

Question
I have several mature barbs. My largest Barb, a green one has what seems to be a wound on its side. The wound doesnt show any flesy, or fungus/bacteria. It looks more like some scales are missing. I added an extra dose of slime coat, and within a day or two it seemed to have more or less healed. Now about a week later it is silver again and not green. I added a slight bit more salt, and also raised the aquarium temp 2 gegrees. He/she seems to spend a lot of time alone, and eats on and off. It is currently hanging out in the bubbles from the airstone...any ideas?

Answer
Hi Darly,
Although aquarium salt is good, in some cases it isn't...your barb has a wound, I would not put too much salt in the aquarium, but now that it is in, you may change 25% of the water.  Is your water condition okay, please check you ammonia level, I cannot stress enough how this is important.  I would bring the temperature back  to 78, and if you can, I would take a q-tip, and dip it in blue methylene and put some on his wound.  Do this twice a day, for three days.  Make another water change, 25%.  I think this will help your fish alot.  Slime Coat if used in too large doses can be harmful to fish.  (I have also used mercurecrome instead of blue methylene, only I did it once a day, and had success - I don't like to recommend this though, but if you see that he is not getting better with the blue met. you could try it once, to see)
Hope this helps
Lynda