Dying grouper help!!!

[fireray]

I have a spotted grouper. I have had this grouper for over 4 months. He suddenly will not eat and it is appearent that he is dying. I know is not ICK. He used eat silver sides. Water conditions are OK. All other fish OK.

 

[peasly1]

have you done a recent water change or anything different lately,have you put any additives in water?