A company began testing technology that uses aeration and microbes in a channel at Otterbein Retirement Community on Grand Lake on Tuesday. Pete Kennedy, left, of Organic Ponds, Bill Rohr, dredge operator at Grand Lake St. Marys State Park, and Tom Grabow, dredge supervisor, discuss the air stations that will be placed in the bottom of the channel. The white box contains the air compressor that will deliver air to the stations.