Oscars with mouth Disease?

I have two baby oscars about 2" long in a 38gallon.
When I bought them they were only 1/2" long so I started
them in a 10gallon. One of them has developped like a
whitish grey tinge on his bottom lip. Is that a fungus or
cottonmouth?

Since then I moved them to a 38gallon. Problem dosen't
seem to be getting better or worst. I am doing a a daily
30% with dechlorinated temp matched water.

Do you think he will recover?
Do Oscars do well with a bit of salt?
If so what concentration?
Is 0.1% typical (1tblspoon/5gal)?

....Kodiak