We haven't had water lilies in the pond for at least three years. Our koi have gotten so large that they tear them up leaf by leaf and kill them in a matter of days. They haven't had a chance of survival, let alone thriving.
After an early spring trip to Memphis Zoo, I noticed wire cages built around drains in their pond. This gave me an idea. As soon as the lilies were available at Trees by Touliatos, we bought one that's hardy in this zone. I took some plastic mesh with 1 and a half inch openings and attached it to the pot with plastic wire ties and closed the vertical seam with the same, and made sure that once the plant was in the water that the mesh would be just a fraction of an inch below water.
I am so happy to see that my handiwork is a success. The lily is thriving. I had 4 or 5 "pads" when we bought it. Now, there are 12 to 15 pads. The mesh has nicely been disguised by a bit of typical moss growth. Plus, I was able to walk out with Billie and Georgia for my morning coffee and plant watering to see this in the pond: