ModelMedia Volume (cubic feet)Surface Area (square feet)Flow Rates (gpm)Growout Feed Rate** (lbs/day)Lbs of Fish Supported*Recirculating Tank Volume (gallonsInternal Sludge Storage (cubic feet)
LPPG 10 10350075-1507.5-15750-15001500-60004
LPPG 17176000130-25511-251300-25002500-100007
* Larger units are custom designed
**Warmwater fingerling to growout includes safety factor


ModelFilter water elevation (inches)Estimated airlift submergence (inches)Minimum fish tank water elevation* (inches)Design airlift flow (gpm)Transfer pipe diameter (inches)Airlift pipe diameter (inches)Airlift air** required (cfm)
LPPG 103835441004625
LPPG 173835441706843
* assumes energy efficient submergence to lift ratio of four and a conservative headloss of across filter of nine inches
**airlift operation only; 3-4 cfm per pound feed required for overall RAS operation

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Our patented PolyGeyser® technology separates the backwash process from water loss. In most filtration systems, solids are purged from the system by draining the dirty water after the backwash sequence. The AST LPPG separates the solids into a sludge chamber, where other solids can continue to collect until the sludge is manually drained. Exclusively draining concentrated sludge minimizes water loss.

The PolyGeyser® filter is a breakthrough in filter technology. It is very different from most filters on the market due to its automatic pneumatic backwash mechanism. Water enters below the bed of enhanced nitrification media and travels upward through the filtration chamber where mechanical and biological filtration take place. Simultaneously, air is introduced into the charge chamber at a constant predetermined rate to achieve the desired backwash frequency.

Once the charge chamber has reached capacity, the pneumatic trigger fires, releasing the entrained air from the charge chamber below the bead bed. The sudden release of air from the charge chamber causes the beads to mix as the air agitates the beads. As the beads drop, the bead bed expands downward while simultaneously water rushes downward through the expanded beads, sweeping the solids away and into the air charge chamber.

In the chamber, the solids settle out from the backwash waters and are later removed from the filter. PolyGeyser® filters recycle the backwash water while concentrating the waste products so that you have extremely low water loss while maximizing the nitrification capacity.

Frequent backwashing has proven advantageous for optimizing the nitrification capacity. Numerous gentle scrubbing cycles promotes a higher rate of nitrification by maintaining a healthy thin biofilm on the surface of the bead media. Typical backwash cycles occur every 3-6 hours.