Cut fresh fish filets are good as well. I use whatever is cheap at the market. Sometimes fresh tilapia filets, sometimes market shrimp, maybe even catfish filets. Just cut it into pieces small enough for him to eat and hopefully he will eat it! If hes been on live all his life it might take some time to get him to take prepared food. Just make sure you get any uneaten bits out of the tank as soon as possible, it will foul the water pretty fast. But if you can get him to eat high quality pellets or food sticks, thats the ticket.