Lily has an aquarium with water, plants, and fish that eat the plants. The aquarium is sealed so no material can get in or out, and has glass sides that allow light to come in. The aquarium can also be covered to prevent light from entering. The number of energy storage molecules in the plants and fish started out low, but that number has been increasing over time. Has the aquarium been in sunlight or has it been covered during this time? What has happened to the carbon in the water?