Answer:
I asked and we got these directions.
Quick Setup Guide
NOTE: The Eshopps Wet-Dry Filter requires an appropriately sized submersible return pump. The maximum flow rate of the pump must match the maximum flow rate of the overflow box for proper operation.
•Unpack and visually inspect the product.
•Install bio-ball media, drip plate, filter pad, and egg crate.
•Set up Overflow Box onto aquarium.
•Securely attach provided flexible drain hose to sump drain tube. Repeat this step for the second hose on Models WD-150CS (#32895), WD-200CS (#32896), and WD-300CS (#32897).
•Place the sump under your aquarium in an aquarium stand.
•Securely attach the end of the drain hose(s) to the Overflow Box drain fitting. (Repeat this step for the second drain hose on dual intake models.)
•Install appropriately sized return pumps (sold separately) in the Pump Chamber. Secure provided return line and nozzle onto the return pump. NOTE: DO NOT plug submersible return pump into power source until pump is fully submersed underwater.
•Start the siphon for the Overflow Box to transport aquarium water to the wet-dry filter.
•Once the return pump is completely submersed, plug return pump into power source.
If you have more questions, please feel free to contact our Customer Service Department at 1-800-443-1160. You can also email them at CustomerService@FosterAndSmithAquatics.com.