Thought I would just tag onto this thread, hoping for some feedback on a similar duckweed situation. My pond is about 1/4 acre and 10 feet deep, only about 5 years old. Last year it started to develop a duckweed problem and this year it doubled down! I've read this is a signal of an eutrophic condition, but the pond is/was all sand bottom and I'm not sure how it could develop this quickly, it is void of almost all other vegetation. I'm speculating that as the water evaporates, it is being replenished from the adjacent wetland (high nutrient content) and not pulling water up from the water table.
I aerate 24/7, but the pond is 100% covered in duckweed at the moment. Does anyone have any experience with this level of coverage combined with aeration? My hope is that the aeration is enough to avoid a massive fish kill? No signs of one yet, I've added a few pictures.
As for treatment, I currently just don't have the time to attempt manual removal, so I've been reading about Reward (diquat) vs Sonar (floridone). I've heard people having success with Reward, but that it is most effective when sprayed on. Is either herbicide method better for mass surface treatment on a body of water with nearly zero water flow? I'm hoping I can possibly just treat the whole pond as no beneficial weeds have developed yet.
