About this experiment
A biosphere is a closed ecoystem, and you can build a miniature one yourself. The plants will thrive, and you'll be able to see the water cycle working up close. Ask an adult for help, especially when using the scissors!
- An empty, clean, transparent 2L bottle
- Charcoal fragments
- Some small plants - ask your parents for some cuttings
- Cut around near the top of the bottle, where it starts to round up towards the lid.
- Add a one cm layer of charcoal pieces.
- Add a 2cm layer of pebbles.
- Add a 5xm layer of soil.
- Use your finger to make some holes in the soil, and add your small plants. These need to be cuttings that will grow, or small rooted plants.
- Tape the top section of the bottle back on.
- Place your mini biosphere in direct sunlight and water it lightly. After that, the water in the container should evaporate and condense on the sides of the container, starting the water cycle. You can water occassionally if you need to.
The charcoal acts as a purifier, filtering the water as it cycles through your little biosphere.