One key as to why the "Advantage
Filter" works so well is it's patent pending internal head 
design.
Its head is designed so that 70% of the water flow is directed straight through
the filter head toward the bottom of the filter. This differs from most other
filters that require that all the water make a sudden 90 degree turn though the
head slots before entering the filter body.
This design accomplishes the following:
1) It greatly lowers the resistance or head pressure.
2) Prevents any sludge buildup in the bottom of
the filter thus eliminating the need for a sludge drain.
3) This causes water to follow the contour of the
filter bottom and therefore evenly distributes it across the beads as it rises
though the filter.
The design of other leading brand bead filters build up sludge in the bottom and require draining out sludge from the bottom drain - not so with the ADVANTAGE bead filter! No sludge buildup! Once again the ADVANTAGE bead filter lives up to its name!
