this is kinda cool, a great teaching aid for understanding ecosystems.
" The Original EcoSphere® is the world's first totally enclosed ecosystem - a complete, self-contained and self-sustaining miniature world encased in glass."
"Unlike an aquarium, this little world is a closed ecological system. Light gets in, but nothing else - no food, no water, no nutrients. Everything must be recycled. Just like the Earth. In our larger world, we also - plants and animals and microorganisms - live off each other, breathe and eat each other's wastes, depend on one another. "