: Plants produce oxygen during the day via photosynthesis. At night, they consume oxygen and release carbon dioxide. Bacteria in the soil also consume oxygen to break down decaying organic matter, releasing the carbon dioxide the plants need to survive.
For aquatic or brackish biospheres. Opae Ula are the hardiest choice. Bottle Biosphere Guide
| Category | Item | Notes | | :--- | :--- | :--- | | | 1-2 liter clear glass bottle or jar | A wide mouth (e.g., pasta sauce jar) is easiest. A carboy (fermentation bottle) looks impressive but requires long tweezers. | | Drainage | Small pebbles or gravel | Washed thoroughly. | | Filtration | Activated charcoal | Crucial. Prevents mold and removes toxins. Available at pet stores (aquarium section). | | Barrier | Window screen mesh or moss | Keeps soil from sinking into the gravel. | | Growing Medium | Potting soil | Use sterile, organic potting mix (no chemical fertilizers or perlite—perlite floats and looks ugly). | | Plants | Small, slow-growing, humidity-loving plants | See list below. | | Water | Distilled or rainwater | Tap water contains chlorine and minerals that build up. | | Tools | Chopsticks, tweezers, small funnel | For arranging inside narrow necks. | | Cleanup Crew | Springtails (optional) | Tiny bugs that eat mold. The single best insurance policy for a healthy biosphere. | : Plants produce oxygen during the day via photosynthesis
Using a funnel, add 2 to 3 inches of potting soil over the mesh barrier. Do not pack the soil down too tightly; it needs to remain loose so roots can breathe and expand easily. Step 4: Prep and Arrange the Plants For aquatic or brackish biospheres
2 cm of pebbles at bottom.
During the day, plants use sunlight to turn carbon dioxide into oxygen through photosynthesis. At night, they consume oxygen and release carbon dioxide through respiration.