Notes

The above photographs show the surface of AFM® , sand and zeolites.  From a biological perspective,  the rougher the surface then the easier it is for bacteria to become established in & on the media.  The photographs clearly show that AFM® has the smoothest micro structure,  followed by sand and then the zeolite.

Clearly the zeolite is seen as a marvellous media for bacteria support, indeed we uses zeolites for the support of autotrophic nitrifying bacteria in activated sludge systems. This property of zeolites makes it difficult to use as an alternative to sand filtration.   The silica sand in the photographs above were of a high quality.  It is anticipated that if a lower quality sand is used,  the surface may have more irregularities.