I dont know much about the pellets and nutrition value , but these guys would need quite a bit to fill em up .
Nls omega one and hikari make great nutritional pellets, just about the best thing u can feed em, a lot of ppl prefer hikari carnivore sticks, there big too. I throw in about 40 pellets everyday and talapia/shrimp every 3 days and they've produced some beautiful piranhas, also 2x a week 50% wc help a lot!
#1 S. Vettel