My kids are raising some tadpoles so far so I've done a lot of reading about them. The best diet would be one that consists of blanched/frozen lettuces like baby spinach, blood worms, and tadpole pellets. Make sure you're removing any uneaten food and do not feed them any floating foods or they may ingest air which could lead to death. Keep an eye on your water quality. Just like with fish, you need to watch your ammonia levels and such. I hope this helps! Good luck!