Eshopps Prodigy External Overflow - Large Eshopps Prodigy Large Ultra-Slim Overflow The Eshopps Prodigy External Overflow - Large combines broad surface skimming with an exceptionally slim internal profile. Its 12-inch-wide internal weir extends only 5/8 inch into the aquarium, preserving valuable display space while transferring water into a clear external overflow box behind the tank. Designed for aquariums from 70 to 120 gallons with flow rates up to 900 GPH, the Prodigy Large uses two 1.5-inch transfer bulkheads and three 1-inch drain bulkheads. This configuration supports primary, secondary and safety drain plumbing while the adjustable weir allows the aquarium operating-water height to be fine-tuned. Prodigy Large High-Capacity Features Ultra-slim 5/8-inch internal overflow preserves aquascaping and swimming space Wide 12-inch weir provides efficient aquarium surface skimming Adjustable weir allows control over the display operating-water level Clear external box allows direct inspection of the drain chamber Recessed external lid helps contain splash and reduce water-flow noise Two 1.5-inch transfer bulkheads move water into the external chamber Three 1-inch drain bulkheads support primary, secondary and safety drains Included drilling template and diamond hole saw assist with installation Eshopps Prodigy Large Specifications Eshopps item number: 95858 Internal box dimensions: 12 x 5/8 x 6 inches Internal metric dimensions: 305 x 16 x 153 mm External box dimensions: 12 x 3 x 6 inches External metric dimensions: 305 x 76 x 153 mm Recommended aquarium size: 70 to 120 gallons Maximum flow rate: 900 GPH Metric maximum flow: 3,407 LPH Maximum aquarium-panel thickness: 5/8 inch Transfer bulkheads: Two 1.5-inch bulkheads Drain bulkheads: Three 1-inch bulkheads See the Eshopps Prodigy Overflow in Action Prodigy Large Drain Configuration and Compatibility The Prodigy Large requires two openings to be drilled through a suitable aquarium panel. Verify that the selected panel is non-tempered before installation because tempered aquarium glass must not be drilled. Allow enough space behind the aquarium for the external box, recessed cover and three drain lines. Select and adjust the return pump so that actual flow reaching the display remains below the overflow's 900 GPH maximum rating. The three drain bulkheads can support a full-siphon primary drain, a secondary open-channel drain and a separate unrestricted safety drain. The emergency drain must remain free of valves and obstructions and should be tested before the aquarium is placed into normal service. Eshopps Prodigy Large Installation Directions Position the supplied template at the intended aquarium water height and confirm that both overflow boxes will clear the aquarium trim, stand and surrounding equipment. Follow the complete Eshopps installation procedure when drilling the suitable aquarium panel. Install both transfer bulkheads and their gaskets while keeping the internal weir and external box level and correctly aligned. Fit the three 1-inch drain bulkheads, install the red safety standpipe and connect the primary, secondary and emergency drain plumbing. Conduct a complete fresh-water test before normal operation. Check every bulkhead for leakage, shut off the return pump to confirm safe drain-down volume and restrict the primary drain to verify that the backup drains can safely handle the system flow. What's Included Black internal overflow box with adjustable weir Clear acrylic external overflow box Recessed clear external-box lid Two 1.5-inch transfer bulkheads Three 1-inch drain bulkheads Bulkhead gaskets Red PVC safety standpipe Diamond-coated glass hole saw Drilling template Installation instructions and warranty information