Our crushed and screened zeolite makes for a superb filter media for the filtration and purification of water supplies. Not only does it perform better than silica or quartz sand in deep bed filters but due to its molecular sieving ability it also removes chemical contaminents associated with bacterial growth and chloramine formation, namely ammonium ions.

Fundamentals of Filtration
Filtration is the separation of a fluid-solids mixture involving a passage of most of the fluid (filtrate) through a porous barrier (filter) which retains most of the solid particulates (cake) contained in the mixture. The barrier may be either :

        a) woven screens (usually metal, cloth or paper)
        b) solid plate punched with holes (usually metal or plastic)
        c) bed of solids (usually sand, coal, garnet, zeolite)

Filter media selection involves the optimisation of these factors
        1. Minimum propensity to bleed
        2. Minimum propensity to blind
        3. Minimum resistance to filtrate flow rate
        4. Resistance to chemical attack
        5. Sufficient strength to support filtering pressure
        6. Acceptable resistance to mechanical wear
        7. Ability to discharge cake easily and cleanly
        8. Ability to conform mechanically to the filter
        9. Minimum cost

Types of Home Residential Filter
Home swimming pools are filtered with a choice of three types of filter. The sand filter is probably the most common, then perhaps the DE (diatomaeous earth) filter and finally the cartridge filter.

The sand filter is a deep bed particulate filter, type (c) above, employing quartz or silica sand as the media. Low maintenance, cleaned by backwashing. High volume throughput.

The DE filter is a fabric filter with the aid of a "precake". The cloth fabric makes is a type (a) filter. The precake is a powder material made from crushed diatoms, dead calcium silicate based sea creatures dredged from the bottom of the ocean. This powder sticks to the outside of the fabric and provides for a better filtration by blocking the larger pores. High maintenance since the whole filter needs to be stripped down before replacing with fresh DE powder on every clean cycle.

The cartridge filter is also a type (a) usually employing a synthetic cloth pleated and rolled into a cartridge. Cleaned by hand. Low maintenance but can be unpleasant since maintenance requires direct contact with dirty cartridge.

Summary of Home Residential Filters
DE filters are probably finished, not only for the high maintenance issues and cost and not for the fact that the DE powder has serious health issues if inhaled but probably because the filtration quality normally associated with DE systems can be readily achieved from a regular low cost low maintenance sand filter if a good quality filter media, such as Zeosand, is used.

Sand filters are very versatile, ideal for swimming pools, spas, fish ponds and potable water weather tank, dam or bore.

Cartridge filters, due mainly to their restrictions in flowrate (factor 3) and dirt holding capacity (factor 2) are best suited to low flowrate low dirt applications on small bodies of water. Small spa baths and final filtration on drinking water for example.

The best all-rounder is the sand filter and the best filter media for a sand filter is probably a good quality zeolite product. The best zeolite product in the world we believe is our very own "Zeosand".