Dog Faced Puffer not eating

[theirr]

I have a 100 gallon tank set up for 1 year. I use a UV sterilizer, wet dry sump, canister filter, power heads, protien skimmer, 50 lbs of live rock, and live sand. First fish in is a Dog Faced Puffer. After that I added:
Huma Huma Trigger
Maroon Clown
Pink Tail Trigger
Harliquen Tusk
Yellow Tang
Hippo Tang
Wrase
Clown Trigger
Had a bit of a problem with ick and added copper for a while. Now that the ick is gone, the copper is out, and water is great the puffer hasn't eaten in a month. He was always been aggresive during feeding time and now he eats nothing and is not excited when I come up to the tank. Nobody is attacking him and I haven't added any fish for several months. What gives? He looks fine but kind of bumps into things now. Has he simple given up?

 

[beth]

Well, could it be copper poisoning? Copper is not the best choice to treat ich. How much did you use, what brand, and for how long?
How's the puffer's teeth? Have you kept them filed down?

 

[theirr]

I used Copper Power, the recommended dosage for several months. A took it out by doing water changes. About 15% a week. As it reached 0 he stoped eating all of a sudden.
I have never heard anything about filing the teeth. I gues you mean give him stuff to wear his teeth down like food in shells?