← Water & Purification
ConditionalIntermediate · 1 hour + 24 hours
The Solar Still
Famous, but very low yield. It can cost more sweat to dig than it produces.
Question 1
The goal
Collect small amounts of distilled water from soil or plants.
Question 2
Materials
- Clear plastic sheet (1.5×1.5 m)
- Container
- Small stone
- Digging tool
Question 3
Substitutes
- Clear bag tied over leafy branch (transpiration bag) — usually better yield
- Rocks to weigh edges
Question 4
Step by step
- 1
Dig a hole ~1 m wide and 60 cm deep in damp, sunny ground — only in cool morning hours.
- 2
Place the container in the center; add green, non-poisonous vegetation around it.
- 3
Cover with plastic, seal edges with soil.
- 4
Place a small stone in the middle so the plastic dips over the container.
- 5
Leave 24 hours. Expect roughly a cup or less.
Saved steps go to My Survival Notebook.
Question 5
The science
Sunlight heats the air and soil under the plastic; water evaporates and condenses on the cooler sheet, then drips to the low point.
Question 6
Dangers & limits
- Digging in heat causes more sweat loss than the still returns.
- Don't add toxic plants or contaminated water.
Question 7
How you know it worked
Clear droplets collect in the container.
My notes
Notes save on this device automatically.