Weeds in the duck hole

[beccrossee]

My hunting group cleaned out around our blind down to the mud by hand. There was a floating mat of sedges,woody weeds, and hyacinth. Everyone assumed it would grow back mostly duckweed before the sedge and hyacinth took over in a couple years. We were wrong... not a speck of duckweed, a few handfuls of hyacinth, sedges around the edges and Copious amounts of Giant Salvinia. Salvinia coverage of the hole doubled in a week. We planned on spraying for hyacinth because the surrounding area is pretty choked with it and would like to open up an alternate boat run. After researching chemicals I think the amine salt of 2,4D was our best/cheapest candidate for the hyacinth. I did the same for salvinia and came up with glyphosate as the best/cheapest way to go. Anyone ever done this? What formulation of glyphosate for salvinia? Any one know where I can find some of those weevils LSU spent $10 million or whatever on? Won't glyphosate kill nearly all aquatic life (crawfish)? Any ideas/ thoughts would be appreciated. Thanks in advance.