The BN is an Algae eater, you can supplement his diet with sinking algae wafers
The Beta will like bloodworm, daphnea and Brine shimp, live or frozen but if frozen defrost and put in the water near the filter to make them move so he can hunt. You should also use Beta pellets as ordiary flake food can constipate him
The hatchets will like Daphnea and Brine shimps or
krill or probably even bloodworms.
The Oto's eat small organisms that live on the leaves of the plants in your tank whos name completely escape me at 1:00am but I sure SDS or one of the other mods will help me out