Sometimes we are our own worst enemy. Fish can go a week or two without food no problem. My technique is pretty simple. First and foremost, I quarentine the fish for two weeks minimum, insuring health is in top condition. I feed live during this time period to fatten the fish up. A water change follows the two week cycle and the addition of active carbon removes any meds in the water. Then, I basically starve the fish for a week, not giving it any food what so ever. On the 8th day, I start adding frozen or pellets. This continues until either the fish accepts the prepared foods, or reaches a poor enough state that I fatten it up with live and start the cycle again.