Each day, it is recommended that we consume more than two liters of drinking water / purified water. Thanks to professionals who work in public health to ensure we have safe drinking water supply, we have enough to drink and meet these needs. Although there's plenty of sources of water on our planet, as we discovered in the videos earlier in the model, water supply in terms of clean/drinking water can be limited in certain parts of the world. Even if it's fresh water, it may contain waterborne diseases and/or other contamination.

So, what will we do if we are in a place where no clean water can be found? How will you survive and secure enough clean water?

This experiment is for survival!! Also makes for a nice TikTok awareness video. If you create one, be sure to share it with us and we may shout you out on Experiment Digital's Social Media platforms!

ATTENTION: Because we won't actually disinfect our water for experiment, and will just be creating a water filtration system, it is NOT safe to drink this water, as this purification and treatment process will not provide safe drinking water. However, the water can be used in irrigation processes (so go water those thirsty plants!!).

If you don't go the TikTok route, we encourage you to create post your experiment videos on this Padlet with narrative, or before/after pictures to show your process and share with us. Ok, let's jump right in:


  • 1/2 L of swamp water or tap water with mud or dirt added (the water quality is not important)
  • 2 L soda pop bottle with its lid
  • 2 L plastic soda pop bottle—cut in half (be careful with cutting and ask someone to provide an extra set of hands to help!)
  • 1000 ml bottle
  • 2 - 20 oz cups
  • 1 tbsp alum (aluminum potassium sulfate)for coagulation: It’s OK if you don't have it. You can use egg shell powder instead (!!!)
  • 2 cups fine sand
  • 1 cup coarse sand
  • 1 cup small pebbles/gravel
  • 1 filter paper or coffee filter (to help serve as a water filter)
  • 1 rubber band
  • 1 large spoon for stirring
  • spoon for scooping the alum

  1. Pour swamp water in the 2-liter bottle with a lid. Notice how it looks and smells.
  2. Put the lid on the bottle and shake vigorously for 30 seconds. Then pour the water back and forth between the two cups about 10 times.
  3. Pour the water into the bottle with its top cut off. Again, notice how the water looks and smells.
  4. Add 2 tablespoons of alum (or egg shell powder) to the water in the bottle with the top cut off. Use the spoon to slowly stir the water for five minutes. What do you notice about the water as you stir it?
  5. Now let the water sit undisturbed for 20 minutes, checking it every five minutes to note how it looks and smells (without moving it).
  6. Use a rubber band to secure the filter paper to the mouth of the bottle with its bottom cut off. Put it upside down in the beaker.
  7. Pour the pebbles into the bottle. Then pour the coarse sand on top of the pebbles and the fine sand on top of the coarse sand.
  8. Carefully pour about two liters of clean tap water through, being careful not to disturb the top layer of sand. Pour the rinsed water out of the beaker.
  9. Pour the top 2/3 of the swamp water through the filter, taking care to leave the sediment in the swamp water bottle.
  10. Once all the water has passed through the filter, compare the swamp water to the filtered water. How do they look and smell different?
  11. Your water filtration instrument should finally look something like this:
    12. filter.png