I hate you! You made me miss my buttikoferi. He looks very nice and at 11", wow, just wow! Get him a 75 or even a 90 gallon. Mine eats large mealworms, krill, shrimp, tilapia (hahaha) fillet and krill.
Yeah, a cannibal, hehehe... I never tried pellets. I know he could have eaten pellets since I saw him feed in the LFS. I hate pellets for clouding the water. I just give it a varied diet of whatever is not a pellet. Its favorite are mealworms. I especially choose the molting ones and give him that. He is quite thick when he reached 8". I only had him for 10 weeks. He grew from 5" to 8" within this short period. Such a shame he turned evil and harassed my severum and my green terror too much. Here he is at 1 week in my tank.
Tilapia fillet is standard fish food for predatory fish. Some find it cheaper than pellets, etc.
Don't feed him for a week then try pellets. You might even try garlic pellets like new life spectrum garlic, sometimes fish love that sometimes they hate it.
It may seem mean but assuming it isn't already starving this fish is fine for up to a month without food.
in their natural habitat, buttikoferi follow hippos and eat their feces. hippos eat grass.. so butti eating soft veggie is logical.
try herbivore foods.
Ya I had also read that they eat hippo poop and thought the same. I believe that they also eat snails and small fish and things. Hopefully I can get him to eat pellets else I will just try to supplement his pea diet with some higher protein food.