I read instructions on a DIY shade sail, but ofcourse it was made out of fabric. It said make a template of the corners, and cut two thickness of fabric for each corner. Sew face to face, 2 sides, turn, and sew this over each corner for re enforcement. Then they used grommets. I could do this with heavy fabric, but afraid after all that work, it would still rip from the stress, flapping, etc. Sounds good for fabric but just not sure about screening. I think I need to think this out better. If the one side of the pond wasn't built like it is with the pavers, I could do like another idea I saw. They used water pipe, the bendable kind. You hammer pieces of rebar in the ground at an angle, and put the waterpipe down over them, to make arches. Then can use anything for the screening. Just make rod pockets, slip the whatever over the water pipe, and stick the waterpipe over the rebar?