Pond Boss Forums INTRO Questions & Observations Duckweed

I have a 5 acre pond covered in duckweed. I can't contact spray it's just too big. I'm thinking of using a trash pump. I know it is only a temperary solution. Any suggestions?

Short term fix - others will provide examples what has worked for them but unless you do something significant expect a return of duckweed. Duckweed is a sign the pond is hyper-nutrient laden with strong indication it is an old pond. With this condition expect the pond from now on to regularly have duckweed problems due to the environmental nutrient condition balance of the pond. Your pond is behaving as a natural aging process for water bodies as over time they collect nutrients and bottom sludge. Long term fix for the pond would be to remove lots of the bottom muck accumulations and/or rebuild it.

Bill has said it all.

As mentioned above, the basis of aquatic growth is organic compost and nutrient rich water. Our acre plus pond finally had a good algae bloom this spring which, when added to the pond weed, finally began interfering with the recreational aspect of our pond. Previously I had used an emergent spray to control alligator weed and arrowhead weed, but it was not effective on the pond weed. We get runoff and ground water from neighbor's cattle pasture so we had a nutrient rich water supply.

Our pond is grassed and mowed regularly to allow access to 90 pus percent of the water and provide a clean walkway. My previous weed control had been emergent spraying and once a year, using a wide, aluminum rake to manually remove pondweed and algae. I didn't want to use a copper based herbicide to control the algae so decided to attack the basis of all the growth and picked up a gallon of probiotic or pond cleaner from my local feed and seed. Both the emergent and pond cleaner products were AquaVet brand, as that is what my feed and seed carried. There are a number of products available that will work, I just took the convenient path using the most available. So, after raking the shoreline I applied the gallon, which was perfect for an acre pond. About the same time we began a three month drought which lowered our pond 24 inches. The pond cleaner did a great job, such that there wasn't sufficient organic material left in the area covered by water to provide a base for pondweed, arrowhead and algae. Between the drought and pond cleaner the pond was basically cleaned of any vegetation which allowed my bass to clean up the small bluegill and small bass. I did get a good bluegill spawn just before the rains came back and raised the pond back to normal level, which provided cover for the bluegill fry.

I was at the pond yesterday and noticed in the zone that the receding water had exposed, now covered in water, algae and pondweed had already emerged from the organic matter that was out of reach of the pond cleanser. I found, in a small pond, a pond cleanser might just work too well. Next year I will leave some areas of cover to see how that works.