Did you know that 75% of the earth’s surface is covered by water? Most of it is salt water and can’t be used for drinking. In fact, less than 1% of the earth’s water can be used by people! Learn how to make your own water filter capable of removing dirt, chemicals, and heavy metals. Try it with our step-by-step instructions and guided scientific questions available in the downloadable support materials, or on the Science-U.org website.