**Airmax Knockdown Defense 2-in-1 Liquid Algaecide for Ponds & Lakes – Fast-Acting Pond Algae Control & Aquatic Weed Treatment – 16 fl oz – Easy-to-Use Liquid Formula for Clear Water – Perfect for Garden Ponds, Koi Pools & Water Features**

Our pond got completely covered by duckweed. I ordered a product from Amazon but it was very expensive and after receiving it and reading the directions I realized that the 5 lb I had ordered wasn't even enough for the first treatment! I would need another 3 lb for one complete treatment! That would have ended up costing a little over $500! Way too expensive. So I returned it and called our county's fish and wildlife office and spoke with a very friendly, helpful biologist who told me the two chemicals that they prefer to use. This product contains one of them. I picked a day when there was no wind or breeze. I did not have to get out on the boat and spread everywhere. I walked along the edge and sprayed out as far as I could with my pump sprayer. I did not even get all the way around, maybe halfway. I did the treatment on a Friday evening and Saturday morning the entire thing was covered in Brown, not emerald green duckweed! Our pond is rain and spring fed and has an outlet on one corner for overflow. So there is some slight current that probably helped distribute the product. I have included pictures which show the pond before treatment, the day after treatment, and 3 weeks after treatment. We went from 100% coverage to approximately 25% coverage in that time. It will take a little more time for the dead duckweed to degrade and sink but it is dispersing even quicker than it grew. Our pond is approximately 1/3 of an acre and a depth of about 15 ft in the middle. The biologist suggested that I use slightly over what was called for in the packaging because of the unusual depth compared to most other ponds in this area plus the fact that there is a slight current. Even so, instead of paying over $500 for one treatment with the other product, I will be able to treat our pond for slightly over 1/5 the price and I will get four treatments!There has been no fish kill or any other consequences noticed from using this product.Overall I am extremely pleased with this purchase! It arrived on time and in perfect condition and worked as advertised.Note: noticed they posted the pictures out of order but I think you get the idea!