We decided to use a copper flower-pot for the weir. We cut a hole in the back and ground it smooth. We used a bulk-head fitting out the back to the pump plumbing. All along the square pot is an inward, 1/2" angle in toward the middle as a slanted inward rim. We cut the front two angles of the rim and bent the lip front down to make the shelf the water falls over. But we didn't account for the new angle of the lip and the gap between the rest of the rim and the lip that water loves to follow down into my dirt and onto the top paver above the waterlin, and all along the front and sides of the tile waterfall weir box we built!!! Update: silicone around the lip and in the gaps and sides of the square waterfall weir. It is losing 2" inches of water overnight!!!!ARRRRGGGGG :cheerful: back to the drawing board.