We applied Aquathol Super K to our 1 acre fishing pond on June 7, 2020 to treat primarily coontail weed which had overtaken the pond. Saw results in 3 or 4 days. Now 3 weeks later the weeds have been completely burned down to the bottom. Too early to tell if they will regrow this season or next but it has done exactly what we hoped. If they begin to grow again, will likely try a systemic (AK is a contact herbicide) herbicide before they grow too much. Todd at Smith Creek was very helpful.