The 31” x 16” Waterfall Weir is a large spillway designed to create natural-looking waterfalls with even flow across the entire width. Engineered for ponds or pond-free systems, it combines stunning visual design with effective bio-mechanical filtration, supporting beneficial bacteria that help maintain clear, healthy water. Its durable, injection-molded housing and compression-seal liner attachment make installation simple and maintenance minimal, with no gluing or complex fittings required.