Loss of appetite and potential increase in mucous

[Little lotl]

I have recently separated my axolotls because of my Melanoid type being potentially bullied. He lost a leg and previously two gills. Once separated he started eating much more and gaining weight. Suddenly 4days ago his skin started having a pale white film on it covering his gills and jaw along with parts of the body. We wondered if this was mucous, and he hasn't eaten now for 4 days. Tank cleaned, water parameters appear good. Not sure what to do, whether salt bath, fridging, is he sick, any thoughts would be greatly appreciated. Thank you.

 

[xxianxx]

Put a pic up, white mucous can be a sign of heat stress , whats the temp ?

 

[Little lotl]

His temperature is about 20 degrees

 

[xxianxx]

Most axolotls are ok at 20c, can you keep him cooler ? Dont bother fridging , salt bathing etc ?