Hand holding a scoop of water in front of mountain lake

Filter Your Water


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We want to travel in space but we have to find a way to gather water. In order for us to be able to drink the water, we need to filter. That is your challenge, create a filtration device to help remove some of the impurities of water you find where you live.


1. Glass jar/clear cup/skinny clear container

2. Bowl/old container

3. Muddy water
a. 4 cups of water
b. Dirt
c. Sand (optional)
d. Pieces of grass

4. Funnel/water bottle cut in half

5. Filtration materials (you can use all of them or only one type):
a. Coffee filter
b. Gauze
c. Cotton balls
d. Sand
e. Small rocks
f. Pebbles
g. Aquarium gravel
h. Charcoal


illustration of a water filter experiment with a plastic soda bottle

Water filtration experiment made from plastic soda bottle


1. Make some nasty water. In a bowl or old container mix up 4 cups of water, ½ cup of dirt, ½ cup of sand (optional), and grass. Feel free to add more dirt, sand, and grass just make sure there is more water than sediment in the bowl.

2. Create your filtration device. Start with either a funnel or bottle. I recommend a 20 ounce soda bottle, but feel free to use something larger.

a. To make your bottle into a funnel just cut in half

3. Now choose your filtration material. The goal should be to use as little filtration material as possible. I am going to use a coffee filter, sand, and aquarium gravel.

4. Make layers in your bottle. I suggest you put cotton, gauze, or a coffee filter at the opening of your bottle so that the rest of your filtration materials do not fall out.

5. Add your layers of materials. REMEMBER, we are not trying to block the water but filter it, so you need to make sure water can get through the device. If it cannot you need to redesign.

6. After creating your filtration device, place it over your skinny clear container and start adding the water.

7. Carefully observe what is happening. Is water making it through your filtration device? Is it still dirty, or is it completely free of dirt and debris?