Excellent link on vegetation. After looking at the pics I really think it is Eurasian Water Milfoil. I will get the rake out on the next good day and clean it up. The water in the jar has been sitting for 12 hrs with no change. The water from the larger pond is pretty clear. Is Milfoil best controlled by manual labor or is there something off the shelf that would be effective? Also will aerating help deal with this stuff?