Eshopps PF-800 Overflow Box Eshopps PF-800 High-Flow Hang-On Overflow The Eshopps PF-800 Overflow Box connects a non-drilled aquarium to an under-cabinet sump, refugium or biological filter without requiring permanent modification to the aquarium. Its hang-on-back U-tube design transfers water over the tank wall and into an external overflow chamber connected to the sump drain. Rated for aquarium systems up to 100 gallons and flow rates up to 800 GPH, the PF-800 provides substantially more capacity than the smaller PF-300. Its slim internal pre-filter box reduces the amount of space occupied inside the display, while the acrylic external chamber incorporates a recessed cover and 1-inch bulkhead connection. Eshopps PF-800 Overflow Features Hang-on-back design connects non-drilled aquariums to sump filtration Maximum flow capacity of 800 GPH for higher-volume systems Smoke-coloured U-tube maintains water transfer over the aquarium wall Slim internal pre-filter box reduces display-space intrusion High-quality acrylic construction supports continuous aquarium use Recessed external overflow cover creates a cleaner installation Cylindrical pre-filter foam helps prevent larger debris from entering the drain Single 1-inch bulkhead provides a convenient drain-plumbing connection Eshopps PF-800 Specifications Eshopps item number: 89024 Dimensions: 8 x 3 x 10 inches Metric dimensions: 203 x 76 x 254 mm Recommended aquarium size: Up to 100 gallons Maximum flow rate: 800 GPH Metric maximum flow: 3028 LPH Intake configuration: Single Drain connection: 1-inch bulkhead Overflow style: Hang-on-back U-tube PF-800 Plumbing and Compatibility/Notes Allow sufficient space behind the aquarium for the three-inch-deep external overflow chamber and drain plumbing. The connected return pump should be selected according to the actual flow reaching the display after plumbing head loss and must not exceed the PF-800's maximum rated capacity. The smoke U-tube must remain completely filled with water to maintain the siphon. Inspect it regularly for trapped air and debris that could reduce water transfer. The complete aquarium and sump system should be tested during normal operation, return-pump shutdown and restart before it is left unattended. Ensure that the sump has enough unused capacity to hold water draining from the aquarium when the return pump stops. Arrange the return outlet to limit backsiphoning and keep the cylindrical pre-filter foam clean enough to avoid unnecessary drain restriction. Eshopps PF-800 Installation Directions Mount the internal pre-filter box inside the aquarium and the external overflow chamber directly behind it. Adjust the assembly using the supplied nylon screw and wing-nut hardware until the boxes are secure, level and positioned at the desired operating-water height. Connect appropriate drain plumbing to the 1-inch bulkhead and route it securely into the sump. Fill the U-tube completely with water and remove all trapped air before positioning it between the internal and external boxes. Start the return pump and verify that the siphon remains stable and the overflow handles the system flow without leaking or excessive noise. Switch off the return pump to confirm that the sump contains all drain-down water safely. Restart the pump and verify that circulation returns to normal. Inspect and clean the U-tube, pre-filter foam and overflow chambers regularly to maintain reliable performance. What's Included Eshopps PF-800 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