Flake or pellet/sticks as the base diet for all my fish; API, Omega One or Wardley's brands. Veggie/spirulina-based for herbivores, basic flakes or pellets for everything else. Tetra Jumbomin for the big fish, 'cuz that's the only prepared food the oscars will eat (long story!) and it's impossible to keep the RD, redhead black belt and other fish in there from eatin' it once it's in the tank.
Coupla times a week, I mix it up. Blanched veggies (squash, cukes, peas mainly) for the herbivores, frozen mysis, frozen blood worms, a variety of freeze-dried foods, frozen shrimp, etc. The oscars love blanched squash!
WYite