How to Remove Salt From Water

The cheapest way to remove salt from water is by using a solar water distiller. Think of a solar distiller as the same natural process of the sun heating water in our oceans, turning it into gas and then condensing into a cloud that drops unsalted water back down to earth. You can replicate this process by following some simple steps. These steps can also be used to remove salt from water in a survival situation.

Difficulty:

Moderate

Instructions

Things You'll Need

• Clear plastic sheet, 5 feet by 5 feet
• Shovel
• Containers to hold water

1. Dig a hole roughly 3 feet by 3 feet and 2 feet deep. If you are in a survival situation and don't have a shovel, use anything that will dig a hole, including your hands. Dig your hole in an area that receives the most sunlight possible.

2. Place you container in the middle of your hole. Make sure your container is dug halfway into the ground so it will not tip over.

3. Use another container to transport the salt water to your hole. If you do not have another container in a survival situation, use the same container you used in Step 2. Make sure the bottom of the hole is thoroughly saturated with the salty water.

4. Place your plastic over the hole. Make sure the middle of the plastic is sagging a bit over your container in the middle of the hole. In a survival situation, any color plastic will work, but it will take longer to evaporate.

5. Anchor your plastic over the hole. You can anchor the sides of the plastic with whichever material you have readily available--tent stakes, dirt, sand, rocks. Just make sure you have a tight seal around the plastic cover so the water vapor cannot escape.

6. Weigh down the center of your plastic sheet. Ideally you can use a small stone placed on the plastic directly over the container in the hole, but you can use whatever you have available to weigh it down in a survival situation.

7. Wait 3 to 4 hours for the solar distiller to complete the distilling process. Your solar water distiller works by the sun evaporating the salty water into a gas (which leaves the salt behind). The plastic cover stops the water vapor from escaping the hole, water condenses on the underside of the plastic, gravity pulls the water toward the center of your weighted-down plastic and the unsalted water drips into your container.

References

• PBS: Solar Still Experiment
• Natioanl Academies: Boosting U.S. water supply

Resources

• Read this Article in Spanish