Wow, my pics really up there, finally! Thank you, El Jefe. Still don't know why I can't get them posted on my own.
I had also sent el Jefe a pic of the lily corral out of the water, which shows the construction better. I've had so much trouble with the pics, I don't know if he got it or not.
It is made of PVC pipe, but a thinner version - it was originally a laundry sorter bin. I threw away the fabric bags, but kept the rectagle frame. I drilled holes in the bottom and side pieces, to let water in to weight it, but kept the top intact, to encourage it to float at the surface. Spray painted it all black. Then used fishing line to sew on plastic screen mesh from Home Depot - like what you would use for a sun / screen porch, or to shade an area. Took two hours, maybe.
It's sitting with its two opposite corners on two milk crates which are at the bottom of the pond, and its height is just right to meet the surface of the water. My two lily pots are inside the corral but on top of the crates, to hold them down. I've got one more lily now, and, since it can't sit on the mesh bottom where there is no milk crate underneath (need to leave room for the fish to swim around!), I have a piece of flat flagstone inbetween the two pots, and will set the new, third pot on top of that.
This gives the lilies and other plants room to spread out, but keeps the koi away from them, and also affords a little protection from moving water outside the corral. I have a few fantails and other small or delicate fish in there. They're quite content, as the mesh allows filtered pond water to move freely through the corral. When toads spawned recently, this was the only place I found eggs.
