Small stationary filters have two main problems: inability to use smaller-size granules and the "channeling" effect.
Smaller-size granules provide a larger area of contact with water within the same filter volume, allowing more effective water purification. Unfortunately, water simply won't flow through a dense layer of tiny granules.
The AQUALEN fibers in AQUAPHOR filters expand in water and break up the layers of granules, enabling water to flow through. In practice this leads to AQUAPHOR filters using granules two times smaller than those in a regular filter, with contaminants being captured four times faster.
The "channeling" effect refers to the movement of loose granules under flowing water. As it passes through the filter, water "parts" the granules, creating channels through which it can flow without making contact with purifying surfaces. AQUALEN fibers are interwoven with the layers of granules to keep them in place. Much like a plant's roots allow it to hold on to soil and prevent erosion, AQUALEN fibers prevent channeling, allowing complete filtration of all water passing through the filter.