My Sick black molly

[kaynick1218]

My black molly has a white spot on the side of its body and the gills where they open up look like they are white. I been treating the tank with copper safe for 3 days now. Should I be worried or should just keep waiting?

 

[pocket22]

My silver molly did this, but died. Gills
Kinda looked gray and behaived the same.