How To Care For A Bull Frog Tadpole?

I got this cute little bullfrog tadpole at the pet store 2 days ago. Im concerned because he is not eating lettuce. So far Ive fed him lettuce and tadpole pellates. He won't eat them! Please tell me anything else i need to know about bullfrogs and bullfrog tadpoles. BEST ANSWER GETS A 5 STAR RATING