How to Use Light to Purify Water

Purify your water with a solar still.

Wilderness explorers and avid campers often enjoy roughing it in the wild. This usually means fishing for food and using a bonfire to cook it. This may also mean purifying your own water if you run out or if you truly enjoy living off the land. Creating a water still that works on light involves a bit of work but is relatively simple. The sun will evaporate the water and pull it up out of the contaminants, making it safe to drink.

Things You'll Need

• Small shovel
• Flat rock
• Large jar
• Dirty water
• Plastic tarp
• Large rocks
• Fist-sized rock

Instructions

1. Dig a hole about a foot deep and wide. Set a flat rock down in the center of the hole. The rock must be flat on one side and at least 4 inches high. Six inches high is better. Make sure the rock is steady and balanced in the bottom of the hole.

2. Set a jar on top of the hole. If you don't have a jar, use a bowl or center your canteen on the rock. Make sure the container is perfectly flat and doesn't slide across the rock's surface when you let go. Pour your dirty water into the hole, making sure it doesn't overflow into the jar.

3. Stretch a corner of plastic tarp over the hole. Make sure the tarp is taut. Weight it around the edges of the hole with large, heavy rocks. Press down on the rocks to secure the tarp tightly.

4. Place a fist-sized rock in the center of the tarp, directly over the mouth of your container. You have to have very careful aim if placing it over a canteen. Press down on the rock so the tarp slopes in toward the center of the hole. Make sure your edge rocks are still steady.

5. Wait several hours and check on the hole. You should see some clear water in your container. The contaminants should be in the bottom of the hole.

Tips & Warnings

• Experiment with light stills at home with bowls and plastic wrap.

• Boil water after distilling for at least 10 minutes. This kills most bacteria and makes water truly safe for cooking and drinking.

References

• The Farm: Solar Water Distiller
• Survival Topics: How to Make a Solar Water Survival Still

Resources

• Build Panel Solar: Solar Water Distiller