i used reward on my duckweed and it was gone with in a few days, i did not have much on the pond. My mix ratio was 12 oz reward to 2 gal h20. Worked very well also took care of some milfoil looking weeds. I scooped it out with a pool skimmer tool. Here is a photo 2 weeks after the fist treatment. (ignore the mess on the edges, pond was dredged this spring and continuing work on it)
