You can train them on prepared foods as long as you have a place to start them out on adult live brine. I have trained more than one mandarin onto prepared foods. I used the same method as Matt Pedersen and Matt Wittenrich who had the article in last months coral magazine. If you want me to post it up LMK. Once you train the fish on prepared foods they are an awesome fish in a nano, so easy to feed. Mine takes formula 1 small pellets, mysis and rods food no problem.