How to Desalinate Seawater


( – To Get the Salt Out of Seawater to Make it Drinkable, What Do You Need?

  • Poncho
  • Bleach
  • Ammonia
  • Jars

Answer: Poncho. Here’s Why…

Every survivalist knows how important potable water is. Water is, after all, life itself. But being surrounded by an abundance of undrinkable water — such as an ocean full of salt water — makes this fact even more apparent.

In a survival situation where seawater is the only available source of hydration, knowing how to desalinate it could mean the difference between life and death. According to the United States Geological Survey (USGS), salt water is toxic to humans when consumed. Normally, the kidneys filter out excess salt using fresh water by way of urination. Without freshwater, this process stops functioning, and multiple body functions become impaired, eventually leading to death.

How to Desalinate Seawater

The best way to remove the salt content from seawater is through a process called distillation: boiling water and collecting the condensation. When the water boils, the salt’s left behind as the water evaporates.

In a survival situation, desalination can be done a few different ways:

    • Container to container. As the following video explains, boiling water in one glass bottle and allowing it to condense in a second, connected bottle, can effectively provide drinkable water. As the water in the first bottle boils, the vapor travels into the second bottle where it will condense. The salt content, being too heavy to evaporate, will be left behind inside the first bottle.

    • Catching condensation. This next method of distillation uses a tarp, sail, or rain poncho to capture water vapor from boiling water. Use the chosen material to create a tent over the boiling water, leaving enough space so it can’t catch fire or melt. The bottom edge of the material should be placed within a receptacle of some sort so that when water vapor condenses, it will flow into the container. If no container is available, the material can be adjusted to create a small pool at the end to collect water itself.
    • Evaporation. If boiling water isn’t an option, distillation can be done using evaporation. To do this, you will need two plastic bottles: a large one and a smaller one. Cut the bottom off the bigger bottle, and the top off of the smaller one. Bend the edges of the cut edge on the large bottle inward to catch the condensation. Fill the smaller bottle with seawater, then place it inside the larger bottle. Leave this in the sunlight to cause the water to evaporate and collect inside the larger bottle. When the water has condensed, remove the inner bottle, remove the cap on the larger bottle, and drink. This process takes longer, but will still get the job done. The following video from Discovery demonstrates this process using two plastic water bottles.

Knowing how to purify water in an emergency can save your life, whether it’s saltwater or stagnant water. To see another option for purifying water in survival situations, check out our article here.

~Here’s to Your Survival!

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