Yes they are a very difficult fish raeh1.
In the wild they pick over rocks for small polyps & crustaceans so most of them are very ready to eat small live shrimp such as mysis. From this they can, as has already been stated, be shown to eat frozen ones, but they can be slow learners and the huge majority of them do not keep up with the other fish & end up starving.
My own one started out eating live shrimp only which I caught in an estuary, he lived in a tank by himself so I could float a few dead ones around without them getting picked off by other fish, eventually the copperband caught on to eating them. Then he went on to shredded mussell and then I started blending flake & pellets in with the mussell so now he eats everything & lives in the main tank with the other fish. It was a long and time consuming process though took about 6 months till it was ready to live with other fish.
Just to show what a hard fish they are though, another member recently asked me if I could train 2 copperbands for him, so I put them in their own tank & started them on live baby shrimps, all went well for a few weeks & then I went to the tank one day & they were both dead of mystery causes . So sad to see such pretty fish dead.
Anyhow the other member decided to try again, bought another 2 copperbands & put them in the tank, again all went well for a while and got them started eating frozen food, then one of them got a bacterial infection which slowly spread over a few days, then the other one got it, & eventually lost both of them .
So the other poor guy had paid for 4 copperbands, with none surviving. At this point I was feeling pretty bad myself over the whole thing and we decided not to try again. :oops: . I don't think any of these deaths were feeding related though, progress was being made but other problems struck.
My own copperband recently went a bit ratty looking but I realised I've been pretty lazy lately and just been feeding it flake for quite a while. I varied the diet giving it some fresh shredded mussell and other goodies & he is now back to his usual self .
Some people have success with copperbands and they are certainly a beautiful addition to a tank but they have to be regarded as one of the hardest fish.