I'm gonna try what my friend told me about. She built with 2x4's across her pond - then put vinyl lattice staple some shading sheets on that. then put plants to cameflouge. (only a small section) NOT the whole thing. She said she has lost less fish to heron since she made that. Plus, she said it give them some extra shade. I guess, this will be my hubbys new project. I know he will be so excited.