Many years ago I had a vision or having lily beds very similar to yours. I bought about $600.00 worth of plants and gleefully put them in pots and into the pond. The next morning they were all gone. I relive the experience when I occasionally find a floating pot or see pics of thriving plants from one end of a pond to the other. Looks like those lily beds go on and on for at least a mile. I'm sick with envy.