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How do you get rid of and keep duck weed out of pond? Pond was recently stocked, I don't have carps. It was dug 16+ ft deep and slopes upward. Bout 3/4 of acre or lil bigger. Need to get it gone and want to keep it gone.

I ordered some of those pellets from the back of a field and stream magazine probably 20 years ago and they seemed to work. Not sure what the active ingredient was. Here's a link that talks about ways to control
http://www.thepondguy.com/category/duckweed

I ordered some of those pellets from the back of a field and stream magazine probably 20 years ago and they seemed to work. Not sure what the active ingredient was. Here's a link that talks about ways to control
http://www.thepondguy.com/category/duckweed

Diquat = Reward
Flumioxazin = Clipper
Flouridone = Sonar


These are the herbicides that will kill it. Active ingredient and then most common trade name. Diquat and flumioxazin are both contact herbicides and chemical must make contact with every duckweed plant for complete control. Check to make sure it is just duckweed and no watermeal (looks and feels like green corn meal) is mixed with it. If you do have watermeal then go with flumioxazin over diquat.

Flouridone is a whole lake treatment option where you bring the chemical concentration in the water up to a certain point and maintain it for 45 days. It will kill all duckweed/watermeal but it's going to cost a good bit more $$$ due to the depth.

All are safe for fish if used correctly. Only way to prevent it from coming back is to make sure the there are no ponds upstream acting as a source and prevent waterfowl from landing in your pond after visiting another pond with duckweed in it.

Reward works great, but as stated, it is a contact aquatic herbicide only, so you must spray it directly on the duckweed.....also, it works best with the addition of a non-ionic surfactant, to aid sticking to the target weeds.