We invented novel bioherbicides for the control of aquatic weeds, such as
Water Hyacinth and Water Lettuce. More than 90% of the weeds are killed
eventually. BRBR

What about water chestnut? It's a terrible problem around here.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)