Have small farm pond (approx 150 by 40 feet) full of Duckweed.
Chemical people said to use Sonar @$178.00 for 8 oz mixed and sprayed with water. Use this year and next and then pond should be goof for 4 to 6 years.

What is avialable or recommed to use organically


Larry

Try the organic herbicide, vinegar, orange oil and soap to a small area and see what happens. You won't hurt anything and you damn sure won't pollute your pond like those chemicals will.
Tony M

Howard was talking about Peroxide.
3% is sold in drug stores. He was talking about 10 or 15 %. Where do you get this from?
Also never heard the diluation rate, since he mentioned this strength is powerful. I would probably mix and spray with a pump up sprayer.

L. J.

You are going to need several gallons of peroxide to oxidize a pond of that size. To quickly oxidize the duck weed you will need to hit dissolved oxygen levels of 10 or 12 miligrams/liter. For reference purposes, under normal cooler conditions healthy streams contain a dissolved oxygen of 6 to 8 miligrams/liter. Duck weed thrives where there is higher than normal nutrient levels. Another way to attack the problem is with some sort of longer term aeration for the pond. Anything that you can do to aerate the water will help. You can buy floating aerators that spray a fountion of water or install a small submersable pump to spray water over the surface.

Is this a recent occurance or has this been happening gradually over time?

waterman

Howard suggested peroxide??? That seems odd since peroxide is a disinfectant - meaning it kills bacteria. Is that the point, to sterilize the water? If you want to kill off everything in the water you can make your own peroxide by broadcasting Oxyclean (as seen on TV) on the surface. Oxyclean cleans clothes by generating peroxide in water.

I've heard Howard recommend the peroxide also. The way I understood this to work was to spray the plants with this strong mixture which would kill the plant. I don't believe the plan is to increase the oxygen in the water. Also, this is only a short time fix, the plants will come back unless other steps are taken. Any one using peroxide this strong (10-15%), keep in mind that it will burn your skin also - be careful!