How to Make a Closed Aquatic Ecosystem. A closed aquatic ecosystem is similar to an aquarium, only it is closed to the outside world so that all the needs of life must be met by the plants and animals within the system.
I want one of these SO BAD! EcoSphere - inside these sealed glass balls live shrimp, algae, and bacteria, all swimming around in filtered seawater. Put it somewhere with some light and they will self-sustain for years, no feeding or cleaning necessary.