I don't know anything about saltwater but I do know that in the freshwater area the success of a tank, from an aesthetic standpoint, is in the eye of the beholder. It seems to me that the decision to go with hi-tech, lo-tech, no-tech or somewhere in between is driven by the desired aesthetic outcome as much as anything. In other words, it depends on what you want. Call me nuts but I bought an eight or ten gallon glass cylinder about 8 years ago at Pier One. I think I put some laterite in the bottom, then a couple inches of eco-complete and an inch or so of grungy mulmy stuff has built up over the years. It sits next to a window and is jam packed with healthy looking Vals that reach to the top -- say two feet. I don't change the water. No filter, no circulation, no extra lighting no ferts -- and no fish except the occasional one who needs a temporary home. I happened to test the water out of curiosity the other day using a test strip and it was the same as my well water. It is really a big vase that has planera, some hydra and some of those little copepod things and a whole lot of other inhabitants that are only visible with a microscope, I'm sure. I had scuds in it but there was a population explosion and subsequent crash. Oh, and there is an amano and nerite in there. In the summer it can get pretty green (and it is a pretty green) but it always sorta fixes itself and, come winter, it clears up. I think it is interesting to watch the way the algae ebb and flow and, all in all, the tank pleases me. (I also like the completely unnatural "nature" tanks that are sustained only be the careful and exacting control of their parameters -- but that is a completely different aesthetic.) I think that when the algae bloom dies it must provide food for the Vals but I've not bothered to research it.