I have a 16 year old 1/2 acre pond that gets covered up with watermeal every summer. This is the small foating green plants-I took a sample to the county agriculture agent. I have heard about SONAR and tried avast(to no avail). I have also heard that barley straw will kill watermeal and is a lot cheaper. Does anyone have any ideas or experience with watermeal?

Thanks for any help