Lauren Fuelling, an intern at the Mercer County Soil and Water Conservation District office, gives a water quality testing demonstration Thursday night in the ag tent at the Mercer County Fair. The demonstrations were given daily for visitors to explain the type of tests that will be performed soon by volunteer qualified data collectors in the Grand Lake and Wabash River watersheds. Volunteers will be testing for amonia, nitrogen, chlorine, phosphorous and dissolved oxygen levels in the water. For information on how to become a volunteer data collector, contact Laura Walker, watershed coordinator, at 419-586-3289.