I feed him shrimp, smelt, beefheart, earthworms, and I used to feed him feeders.
I'm guessing you will have to start a small on on feeders and slowly try to get them on shrimp.
I got mine to take shrimp by tieing it to a fishing line and making the shrimp look "alive"
You can expect to see it at a foot or so in about a year. They're pretty quick growers
Mine is about 18-19" at the moment, but his growth rate is fairly slow now.