Students will work in groups to collect water from different areas in a watershed and measure the following characteristics: pH, salinity, dissolved oxygen, and temperature. Students then construct a water filtration apparatus and observe changes in the listed characteristics based on filtration. This activity guides the students to understanding the differences in water quality in various locations within the watershed through investigation and collaboration.

Prior to teaching the lesson, teachers should have a basic understanding of the watershed where the water will be collected. Detailed information can be obtained from the water management district. See for links to Florida's water management districts.

Ideally, the water should be collected by the students from a site on or near school property. Be sure to follow school and district guidelines for field work.