A "Nature Aquarium" is, as far as I can tell, an Amano concept. It is an aquarium aquascaped to look like a non-aquatic scene in nature. Like a forest, with a trail or stream going through it, or a mountain, etc. Amano used CO2, moderate lighting, and lots of work, plus outstanding photographic skills. I don't see any way to create something like that with low light and minimal tank maintenance.