We had water hyacinths in our acre-size pond for a couple of years. We had to corral them in close to shore using floating ropes tied off to the banks. Otherwise, they would have taken over the whole pond. They were my Hoosier wife's idea. She thinks they're lovely. I, being a native Floridian and having seen miles-wide rivers made impassible by the things, want no truck with them. Fortunately, we're in northwest Florida, not the peninsula, and it gets cold enough here to knock them back pretty hard in the winter. They didn't survive the second winter. I'm glad.