Use a glass carboy. Fill with aquarium gravel, pond water, Elodea (aquatic plant), one Neocaridina shrimp, and Ramshorn snails . Seal it completely. The shrimp eats algae; the snails eat dead plant matter. Provide LED light for 10 hours/day.
Sealing your biosphere is what transforms it from a simple terrarium into a true, self-sustaining world. Once sealed, it should only ever be opened for emergencies or significant rebalancing. The goal is to lock in the perfect amount of moisture and air forever. Any clear sealant or cap that creates an airtight seal will work, such as a rubber stopper, a cork sealed with silicone, or a screw-top lid reinforced with tape. Once sealed, the water cycle begins: the sun warms the air inside, water evaporates, condenses on the cool glass walls, and "rains" back down onto the soil, perpetually recycling. bottle biosphere guide full
: Sun warms the jar. Water evaporates from the soil. Moisture condenses on the glass walls. It drips back down like rain. Use a glass carboy
A funnel or a rolled piece of paper for pouring soil cleanly. A long stick or spoon to compress the substrate. A spray bottle filled with distilled water. 3. Selecting the Right Plants and Microfauna The shrimp eats algae; the snails eat dead plant matter