Global Water Quality Science Experiment Learn how science can be used to give people around the world access to clean water.Join a Global experiment scientist, educators, and students around the world are uniting to conduct the largest experiment ever. The subject is water, our most precious natural resource, and this kit offers you the tools you need to participate. Test water quality with pH and carbon dioxide analysis. Build a water filter tower to clean dirty water. Experiment with water purification by evaporation Check out my other listings and I will combine shipping for only $1.50 in the U.S. Thanks for looking!