Donald from Otsego, Mi writes
Diquat Water Weed and Landscape Herbicide is a great option for duckweed in ponds as directed on the product label. For duckweed control, apply Diquat Water Weed and Landscape Herbicide at 1-2 gallons per acre plus 32 oz per acre of surfactant in at least 100 gallons of water. Treatment of dense weed areas may result in oxygen loss from decomposition of dead weeds. This loss of oxygen may cause fish suffocation. Therefore, treat only 1/3 to ½ of the water body area at one time and wait at least 14 days until the next application.
Answer last updated on: 07/18/2018
