Prepare your FIT system’s location. The tank must be installed on a level surface to facilitate airlifted water circulation. The filter backwash and airlift performance is contingent on the filter being level.
The beads will be shipped in boxes alongside the filter. Beads can escape through the inlet piping to the filter chamber. To prevent this, close any open ended pipes leading to or from the filter chamber. Beads should then be added to the filter chamber and the screen mounted and bolted down.
Attach air supply line to the ¼” barb connector. Install the air pump above the water level to prevent backflow flooding in case of power shortage. Air check valves are shipped standard with the unit, and are intended to protect the air pump from backflow. Install them between your air pump and the unit to avoid damage to your air pump.
Fill with water to the midline of the outlet return pipe within the tank.
Set the backwash air feed rate at the maximum to achieve the highest backwash rate attainable with your setup (possibly as much as once every 15 minutes). Let the unit operate in this manner for 12-24 hours, more if necessary. This allows the beads that have moved into the charge chamber to go back to form the filtration bed. Under normal operation the bead bed is formed by simple buoyancy. There is one screen in the head designed to constrain the beads. The unit’s pneumatic and hydraulic behavior is designed to substantially confine the beads to filtration bed. During shipping, a substantial proportion of the beads fall into the charge chamber where they are trapped (by buoyancy) in the charge chamber. So when the tank is first filled, perhaps fifty percent of the filtration bed is in the charge chamber. The unit’s trigger is designed to pass beads from the lower chamber, but only at a handful per cycle. The system must be operated at a high backwash frequency for a time to readjust the unit’s internal balance and move the beads back to the filtration chamber.
Adjust the backwash pump’s air flow down after the first day, so that the filter backwashes two to four times daily. Your application may benefit from adjusting the backwash frequency up or down depending on loading (mass of fish and feeding amounts).Remember to add water conditioner prior to adding fish. Fish can be added at reduced loading, or the system seeded with bacteria or chemicals (ammonia, nitrite) to encourage the development of biofilm for biological filtration. See Acclimating your filter for more details.
Sludge is generated and stored within an isolated sludge chamber. This sludge can be used as fertilizer for plants. In aquaculture applications, sludge production is estimated at 3-6 gallons per cubic foot of beads per day at design capacity (1.5 lbs feed/ft3-day). Sludge handling should be sized for a generation rate of about 10 gallons per cubic foot of beads per day. See sludge removal options for more choices including pneumatic sludge exchange or sludge discharge.