my discu fish skin peeling off at the side

[Doreamon]

Hi all

I have two discus fish in my 2ft tank. After 50% water change four days ago ,I have one of the discus was behaving weird-like swimming near the top of the tank and hanging in the upper corner.

When I look at the discus ,its sides look like they are peeling. Like white, flaky dead skin on the side. Any idea what that is.

[bosebani]

Any pictures? Sounds like ph shock

[Doreamon]

pic.jpg

The pic of discu skin