Looks very similar to what I had in my pond this summer. Either the widgeon grass mentioned or sago pondweed I believe. I had it around nearly 75% of my 1/2 acre pond and spread 40 lb of Hydrothol and within 1 week it was pretty well gone. It will spread fairly quickly. I tried pulling it out but it just seemed to make it spread faster. I know you can buy a weed cutter to trim it off, but I decided to kill it. We'll see if it comes back next year.
Guess you could selectively spread the Hydrothol and try to keep some areas if you don't want to rid your whole pond. But it will spread on you so keep an eye on it!!

Last edited by Brian S.; 08/31/09 08:34 PM.