Eshopps PF-1000 Overflow Box Eshopps PF-1000 Dual-Siphon Overflow The Eshopps PF-1000 Overflow Box provides a convenient way to connect a non-drilled aquarium to an under-cabinet sump, refugium or biological filter. Its hang-on-back design uses two smoke-coloured U-tubes to transfer water over the aquarium wall without permanently modifying the tank. Designed for aquariums up to 150 gallons with flow rates up to 1,000 GPH, the PF-1000 combines a slim internal pre-filter box with a high-quality acrylic external overflow chamber. Dual intakes and two 1-inch drain bulkheads provide the capacity required for larger aquarium systems while requiring only approximately three inches of clearance behind the tank. PF-1000 High-Flow Overflow Features Hang-on-back configuration adds sump filtration without drilling the aquarium Dual U-tube intakes provide increased water-transfer capacity Two 1-inch drain bulkheads support high-flow sump plumbing Slim internal pre-filter box reduces intrusion into the display aquarium Smoke-coloured U-tubes provide a clean and unobtrusive appearance Recessed external-box cover helps reduce splash and operating noise Cylindrical pre-filter foams help prevent larger debris from entering the drain plumbing Adjustable mounting hardware helps establish the desired aquarium water level Eshopps PF-1000 Specifications Eshopps item number: 89034 Dimensions: 9 x 3 x 10 inches Metric dimensions: 229 x 76 x 254 mm Recommended aquarium size: Up to 150 gallons Maximum flow rate: 1,000 GPH Metric maximum flow: 3,785 LPH Intake configuration: Dual U-tubes: Two Drain connections: Two 1-inch bulkheads Overflow style: Hang-on-back siphon overflow PF-1000 Plumbing and Siphon Notes The PF-1000 requires sufficient clearance behind the aquarium for the external overflow box, bulkhead fittings and connected drain plumbing. Select a return pump according to the actual flow reaching the display after vertical head pressure and plumbing resistance are considered. Both U-tubes must remain completely filled with water to maintain continuous siphon flow. Inspect them regularly for trapped air, algae and debris that could reduce the amount of water transferred to the external box. The sump must have enough unused capacity to hold all water that drains from the aquarium when the return pump stops. Always test the complete system during normal operation, return-pump shutdown and restart before leaving it unattended. Eshopps PF-1000 Installation Directions Position the internal pre-filter box inside the aquarium and hang the external overflow chamber directly behind it. Adjust the mounting hardware until both sections are stable, level and positioned at the desired operating-water height. Connect suitable drain plumbing to both 1-inch bulkheads and route the lines securely into the sump. Fill both U-tubes completely with water, remove all trapped air and position them between the internal and external boxes. Start the return pump and confirm that both siphons remain stable without leaking or exceeding the overflow's rated capacity. Switch off the return pump and verify that the sump safely contains all drain-down water. Restart the system and confirm that normal circulation resumes. Inspect and clean the U-tubes, pre-filter foams and overflow chambers regularly. What's Included Eshopps PF-1000 internal pre-filter box External overflow box with recessed cover Two smoke-coloured U-tubes Two cylindrical pre-filter foams Two 1-inch bulkhead fittings Nylon screw and wing-nut adjustment hardware
