Self-contained worlds

An ecosphere is a self-contained world that contains plants and animals inside a completely sealed container. They can live for decades, without ever opening it up to feed or clean. The algae make food for the tiny brine shrimp, and the shrimp make carbon dioxide for the plants. Together they make a circle of life. I’ve had ecospheres on my desk for 30 years. Until I inadvertently killed it, one of mine lasted 25 years. I’ve bought small ecospheres and “repotted” them in larger vessels, but even small ones can last many years. A good deal for a small ecosphere is Shrimp Bubble, which comes with an internal magnet to clean the inside glass without opening it. — KK