Adding salt to the water helps the fish to stabilize their system. basically it allows them to spend more energy on healing rather then maintaining their system. I had a albino Oscar at one time that came with it. I absolutely could not get it to go away no matter how clean I tried to keep the water. Once I added salt in the tank, it disappeared. I would def. recommend trying it, it does not hurt anything. Get a box of Kosher salt though, don't spend the extra money on aquarium salt, and I would not use table salt because it contains iodine.
Hope this helps...