My aro is about 14 inches .
The bichirs are small reaching from 6 to 10 inches .
I could get the Polyuranadon with maybe 10 inches.
At first i was afraid that my bichirs get eaten from my other fishes but it worked well.
I dont know if my bichirs grow much faster than a palyuranodon.
I have endlis, weeksi,lapradei,delhezi.
If u just got him just wait on it it may take a week for him to get settled in or longer. Try hikari carni pellets or broken up massivores. Sinking food is easier for them to eat but it's more fun to watch them eat floating sticks.Thanks for the info... Maybe its something im doing thats throwing him off... Maybe i'll lay off the tank and just throw in floating food and see if he eventually starts going for it