Well I was thinking about getting a very large aquarium that would sustain itself in every way except heating and lighting. I would like a more natural aquarium where there would be only live food and no equipment other than a thermometer and lights. I think it would be awesome if it worked but it sounds like it wouldn't from what everyone has said. But if variety is the problem, what about a good amount of breeding pods, brine, mysid, grass shrimp, and anything else that is alive? With many live organisms plus algae there would have to be variety in the livestocks' diet.