Hang pre-filter on back of aquarium after attaching siphon overflow box to pre-filter box. Place siphon tube (U-tube) into pre-filter box and connect one end of the spiral drain hose to the slip fitting of the pre-filter and the other end to the bulkhead on the main filter below.
Attach black adjustable return spout to one end of vinyl tubing (return line) and the other end of the vinyl tube to the return pump (sold separately).
Attach 1/4" vinyl tubing to remote drain (barbed output) on protein skimmer cup. Place other end of vinyl tubing into a remote collection container such as a 2-liter plastic soda bottle.
Start siphon. Add more water directly to the sump if the sump does not fill with enough water to cover the return pump.
Start pump and protein skimmer once the pump is covered with water and is completely submerged. Continue adding water to sump until the water line mark is reached.
Adjust the black air valve leading to the venturi valves on protein skimmer. System is now operational.