Having no clean drinking water during an emergency can be fatal, so it's important to know how to make a water filtration system when necessary. Whether you already know how to make one, or you're a first-timer, we’ll help you design a water filter for your needs during a crisis situation.
IMPORTANT SAFETY NOTE: These DIY filters are not designed to make water drinkable. Even if your filtered water looks clean, it may still contain unseen pollutants. Drink at your own risk!
Materials Needed
- 2 empty plastic water bottles
- Scissors
- Towel or paper towels (for spill cleanup)
- Gauze or cheesecloth to cover the mouth of the bottle
- Rubber bands
- Filter materials (e.g., sand, rocks/gravel, cotton balls, etc.)
- *If you don't have all the materials, get creative and substitute with items you have around the house.*
Creating a Dirty Water Sample
To create a dirty water sample, mix soil with water. For a more challenging filter test, add other materials like food coloring, oil, or vinegar to the water.
Building Your Water Filter Cartridge
Start by carefully cutting your plastic water bottle in half. Remove the cap and place gauze or cheesecloth over the mouth of the bottle. Secure it with a rubber band.
Turn the top half of the bottle upside down and place it into the bottom half of the bottle. If you'd like to fit more filter materials, consider using two bottles. Clear containers are recommended so you can see the filtration process as it happens.
Designing Your Filter / Test and Evaluate Results
Add your chosen filter materials (sand, gravel, cotton, etc.) to the top of your filter cartridge. Then, pour your dirty water into the filter and observe the results. Depending on the materials you used, you may need to filter the water multiple times to improve clarity.
IMPORTANT SAFETY NOTE: These DIY filters are not designed to make water drinkable. Even if your filtered water looks clean, it may still contain unseen pollutants. Drink at your own risk!
Practice Makes Perfect
Based on your testing and observations, adjust your filter materials and methods as needed. Try using different materials and water amounts to see what works best. The goal is to produce the cleanest water possible in one filtration attempt.
Source: NASA