Manny, Gary has it in a nut shell there. The thing is, if you have multiple different kinds of feeders in your tank, you need to feed them all. They all eat different primary foods and there is some overlap. If you have live rock, you need to feed the creatures in the rock. It will turn out beautiful, even if its a cultured LR tank, if you use a variety. Almost all of our tanks have things in them that directly benefit from a microphyto-plankton like DT's. Then in turn, those things grow, reproduce and make a real food chain in your tank. Other animals need the zooplanktons, basically all the other things Gary listed. The things he listed are all different sizes. Size can be a big deal to some animals. Some large anemones eat microplankton, but who would guess that? A reef keeper has to know about what is in the tank to feed it and keep it long term. The more dynamically stocked the reef is, the better, and the higher the need for all the sizes and types of foods.