Rot?

[DarkSeraph]

I have a few fish that have been showing some signs of discoloration, almost like a rot. It's not fin rot because it doesn't appear on their fins at all, however 2 of my bala sharks and my 3 spot gourami have signs of it.

Here are the pics of the bala shark with the worst of it:

...ignore the unhappy plant... I'm working on it

So what could it be, and how can I fix it?

 

[WILDER]

It's looks like velvet to me as the patches look rusty, are they flicking and rubbing against objects, velvet is worse than whitespot so you need to act fast.

 

[nath1]

i had a recent incident with two of my bala sharks, both small, where they seemed to lose thier colour on thier heads and eventually the black in their fins went as well. the scales on their heads seemed to go see- through! it happened at different times and on both cases i placed the shark in a bag floating in the tank with some aquarium salt(about 1 table spoon) mixed in, for about an hour. in both cases the shark made a full recovery and regained all its former colour! i dont know if the salt helped or if the shark just recovered but it certainly didnt do any harm.
good luck,
nath1