Eshopps PF-300 Overflow Box Eshopps PF-300 Hang-On Sump Overflow The Eshopps PF-300 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 transfers aquarium water over the tank wall through a smoke-coloured U-tube, eliminating the need to drill the aquarium panel. Designed for aquariums up to 75 gallons with a maximum flow rate of 300 GPH, the PF-300 uses a slim internal pre-filter box to reduce the amount of space occupied inside the display. The external acrylic overflow chamber incorporates a recessed cover and a 1-inch bulkhead connection for convenient drain plumbing. Eshopps PF-300 Overflow Features Hang-on-back design adds sump filtration without drilling the aquarium Smoke-coloured U-tube transfers water between the internal and external boxes Slim internal pre-filter box reduces intrusion into the display aquarium High-quality acrylic construction supports dependable aquarium use Recessed external-box cover provides a clean low-profile appearance Cylindrical pre-filter foam helps reduce debris entering the drain line Single 1-inch bulkhead supports convenient sump plumbing Designed for quieter operation when properly installed and adjusted Eshopps PF-300 Specifications Eshopps item number: 89014 Dimensions: 6 x 3 x 10 inches Metric dimensions: 152 x 76 x 254 mm Recommended aquarium size: Up to 75 gallons Maximum flow rate: 300 GPH Metric maximum flow: 1135 LPH Intake configuration: Single Drain connection: 1-inch bulkhead Overflow style: Hang-on-back U-tube PF-300 Plumbing and Compatibility/Notes The aquarium must provide sufficient clearance behind the tank for the external overflow chamber and connected drain plumbing. The PF-300 requires a return pump and sump system capable of operating within its 300 GPH maximum flow rating. The U-tube must remain completely filled with water to maintain the siphon between the internal and external boxes. Air accumulation inside the U-tube can reduce flow or interrupt the siphon. Test the complete system after installation and following a simulated power interruption before leaving it unattended. The aquarium and sump must contain enough empty capacity to accommodate drain-down water when the return pump stops. The return outlet should also be positioned or protected to limit backsiphoning into the sump. Eshopps PF-300 Installation Directions Hang the internal pre-filter box inside the aquarium and position the external overflow chamber directly behind it. Use the supplied adjustment hardware to establish the desired operating-water level and ensure that both sections remain stable and level. Connect suitable drain plumbing to the 1-inch bulkhead and direct it securely into the sump. Fill and prime the U-tube completely so that no trapped air remains, then place it between the internal and external boxes. Start the return pump and confirm that the overflow maintains a stable siphon without leaking, gurgling excessively or exceeding its rated flow. Test the system by switching off the return pump and verifying that the sump safely contains all drain-down water. Restart the pump and confirm that normal circulation resumes. Inspect the U-tube and pre-filter foam regularly and clean them before debris or air accumulation restricts flow. What's Included Eshopps PF-300 internal pre-filter box External overflow box with recessed cover Smoke-coloured U-tube Cylindrical pre-filter foam 1-inch bulkhead fitting Nylon screw and wing-nut adjustment hardware
