Prepare your LPPG system’s location. The tank must be installed on a level surface. 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.
Choose a configuration from Plumbing configurations; either water pumped or gravity
fed airlift (see plumbing configurations for details) Attach air supply line to the barb
connector. Install the air pump above the water level to prevent backflow flooding in
case of power shortage. Air check valves should be used to protect the air pump from
backflow. Install them between your air pump and the unit to avoid damage to your air
pump. Valves on airlines to allow for airflow adjustment.
Fill with water to the midline of the outlet return pipe within the tank. See setup
diagram for your configuration for further details.
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
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 About sludge removal for information about sludge discharge.