The Freshmen in the Water class are studying the water cycle. In the process, students learned that infiltration is an important part of the cycle because as the water passes through layers of soil and sand, it is filtered and purified so it can be consumed. Using that information, students built water filters to address the guiding question, How would you cope in a water crisis?. As a part of this investigation, they studied pH levels and how to determine if the water is potable. After they designed and built their filters, the students attempted to turn non-potable water into potable water.