Thanks for the replies!
Both Pendimethylin (Scotts Halts) and Dimension mentioned fish toxicity, so I was wary of those. I don't want to be responsible for any kills or three-headed bass. The dam has had no maintenance done other than mowing for the 6 years I've been here and probably another 4 years before that and it looks it. I'm volunteering as caretaker for the dam and learning as I go.
The Prodiamine (Barricade) sounds great, low toxicity and an eight month effectivity. What Prodiamine only products can be spread with a fertilizer spreader? A Prodiamine/fertilizer combination should be perfect for a September application here in central Georgia.
Ted, do you know of a Prodiamine/fertilizer that is readily available in stores?