Clown fish has a diseases, but im not sure what it is

[Xbreex]

My clown fish has been doing perfect for about 1
Month. Then me and part of my family left for 2 days and left my dad in charge... The fish has spots and pelling! Its hard to get a picture . The water tested perfect except a few pointsoff salinity so i fixed that. My tank is a 20 gallon and only has that one clown , 1 six line wrasse and 1 cleanershrimp. I just did a 3 gallon water change. I put one photo out, im not sure how to add more..Can yall help me save nemo?

 

[Ginger bay]

Take him out, put in bare hospital tank and treat with coppersafe, copper power or similar.

 

[ThRoewer]

Looks like ich. I would rather recommend Chloroquine Phosphate than copper, especially with a clownfish.