The Ammonia Tower is basically a tall, skinny version of the SweetHeart filter. More media, in a smaller footprint and a longer water fall inside make it worth the extra few dollars.
The Ammonia Tower is a high fall filter, which means most of the media will be wet, but above the water line inside. This means it capitalizes on the "wet-dry" concpets of filtration and has a high aerobic capacity.
Water flows to the top of the unit and then out through a spray bar. Down through a 3" thick layer of ROCF and then a layer of white Japanese matting. Finally, it meanders through 200 square feet of Bio Flo media giving up its nitrogen, and back to the pond.
This design has been pushed and carried fifty pounds of fish with moderate feeding.
The tower itself is 13" in diameter and stands 25" inches tall. Pump is not included.
In the image above, the brown "thing" is just a standard masonry brick to give you some impression of the size of the unit.
Can be used alone, or with another filter for additional nitrogen reduction. Specialty: Nitrite reduction.