Making Fresh Water with a Solar Still
What if you were stranded on a desert island? You had no fresh water to drink.What would you do? Where would you find water? How would you survive? Could you survive without water very long?
You might say "Well if I am on a desert island there is water all around me." That would be true but you cannot drink salt water. You have to have fresh water to drink.
Water is one of our natural resources and we need it to live. Our bodies are made up mostly of water. We can go a long time without food but we cannot go more than three days without water before we die.
There are special machines that can make fresh water from salt water. The Navy has special ships that have these machines on them. They often go help out in natural disasters, like hurricanes, when water and power systems are not working.
Try making your own fresh water with this solar still. It is a fun and easy experiment to do.
Materials you need:
- Table salt
- Paper cup
- Plastic spoon
- Large plate
- Saucer
- Metric ruler
- Large clear bowl
What you do:
- Fill your paper cup half way full with warm water. Add two spoonfuls of salt to the water and stir well.
- Put the saucer on top of the large plate. Set these in a sunny place – you want it to get a as much sunshine as possible.
- Pour the salt water from the cup into the saucer until you have about 3 millimeters of water on the saucer.
- Put the large clear bowl upside down over top of the saucer and plate. It can rest on the large plate.
- Observe your solar still over the next week. What happens on the large plate? What do you see on the glass bowl?
Questions:
- What do you think happened to the water on the saucer?
- What type of water do you think is on the large plate? Fresh or salt? Why? Taste it and see if your answer was correct.
- What gave the solar still the energy to work?
- If you were stranded on a desert island with very little material to work with what are some ways you could make a solar still and have fresh water?
More ideas:
- Do some research on the desert. How do the animals and plants that live there survive without an abundant supply of water? How do they find water in a place that is dry most of the time?
- How do farmers get water to fields when there is no fresh water supply?
This is a great science project for cub scouts, boy scouts or 4-H. Could also be used as a science fair project. Watch for more fun science experiments and projects with boys in mind!
