Reward Aquatic Herbicide 1 Gallon Active Ingredient: Diquat - Non Toxic to Fish. Manages weed problems in aquatic, grounds maintenance and landscaping areas. Great for Golf Course Landscape Management, Amusement Parks and other Recreational Facilities Can be used along the edges and non-flooded areas of ponds, lakes, drainage ditches and canals Once applied, it diffuses rapidly through the cuticle and then throughout the leaf tissue of the weed. The first effects can be seen within an hour Complete control of floating vegetation occurs within one to five days, while submerged weeds require approximately five to 15 days for control. Not for sale to WA.