Scratch? bite? something bad?

[Nozebleed]

Hi, My newly acquired jardini has began to scratch..he seems to have developed a white blotch on his back..not sure what it is. maybe you guys can tell me if its something serious. he's also rubbing now and then just behind his gill..i cant see any obvious irritant. and the camera doesn't show anything either(bottom photo).
Should i panic!!!? Or is this normal...maybe just the fish getting used to new tank?

 

[josue25]

he looks like his missing a scale \

is it eating fine ?

 

[phobull]

Yeah just a missin scale my silver has that but its recovering.

 

[Nozebleed]

yeah...he's starting to get his appetite after 4 days in the tank..but he is doing a little scratching just behind the head area. seems to be calming down though. i was thinking of adding adding some salt...i'll wait until next saturday and if he's still rubbing i'll add a dose. he is swimming around in good humour. seems happy enough. I did have a mean syno catfish in there...but i took him out. i think he may have had a nip...will the scale grow back?