Bottle Biosphere — Guide

High-quality, sterile potting soil mixed with perlite for aeration. Avoid soils with heavy synthetic fertilizers. Long tweezers or aquascaping tongs. A funnel or paper cone for pouring soil cleanly.

| Problem | Likely Cause | Solution (if unsealed) or Prevention | |---------|--------------|--------------------------------------| | Algae bloom (green water) | Excess light/nutrients | Reduce light; add more grazers; use charcoal | | Foul smell (rotten eggs) | Anoxia, sulfate reduction | Unseal temporarily, increase air space | | Dead animals within days | Overcrowding, ammonia spike | Start with fewer organisms; cycle bottle 1 week before animals | | No condensation | Leak or too dry (terrestrial) | Reseal; mist lightly if semi-open | | Mold (terrestrial) | Too wet, no springtails | Add springtails; reduce watering; increase airflow briefly | | Plants yellowing | Nutrient deficiency | Could be natural; if severe, add tiny amount of aquarium fertilizer before sealing | Bottle Biosphere Guide

—teaching others about closed ecosystems promotes science education and respect for natural systems. High-quality, sterile potting soil mixed with perlite for

| Container Type | Pros | Cons | Best For | |----------------|------|------|-----------| | Glass mason jar | Cheap, easy to find, seals well | Small size limits plants | Moss gardens, small trials | | Large apothecary jar | Beautiful, wide mouth for planting | Expensive | Showpiece terrariums | | Round carboy (3-10 gallon) | Dramatic shape, large volume | Hard to plant through narrow neck | Advanced projects | | Recycled glass bottle | Free, eco-friendly | Neck often very narrow | Challenge builds | | Plastic soda bottle | Free, unbreakable | Scratches easily, less clear | Kids' projects | A funnel or paper cone for pouring soil cleanly

If you reach this point, your biosphere will likely last years.

Your soil should be damp but not wet—like a wrung-out sponge. Too much moisture causes rot; too little desiccates plants.

Sunlight heats the interior, causing moisture to evaporate from the soil and transpire from plant leaves. This vapor condenses on the cool glass walls and trickles back down into the soil, creating a continuous cycle of rain.