If you want him to start eating pelletized or frozen food - simply put - stop feeding him guppies. Get him used to the idea that your presence in front of the tank means food is coming - drop in a few pellets and he should strike. If not, keep coaxing him and conditioning him to associate you with food. I would also be amazed if he would not take frozen bloodworms - there are few fish that wouldn't. Nice jag too - keep us posted & good luck.