RTR nailed it (as usual ). Some great foods are snails, to keep their beaks trimmed, shrimp from your local grocery store, my puffs have always loved this, and just about anything else you can think of. To keep their minds stimulated you can feed live ghost shrimp (glass shrimp), puffs love chasing them! Anyway hope this helps and good luck with a Puff if you have one!
Bloodworms and ghost shrimp are not heavy enough crunch to control an F-8's incissor growth. You really need to include a significant percentage of snails in the diet.