To say the least, Carbon is an amazing thing! Most every living thing is made from hydrocarbons because carbon is an excellent building block containing four friendly electrons that Carbon [C] doesn’t mind sharing. Carbon comes in three natural forms, first is Diamond – an extremely hard substance (and valuable too!), then Graphite – an excellent lubricant to keep things running smoothly, then its broadest form, which is Amorphous Carbon. Although the first two forms are excellent for many things, they do not filter water well. But, this is where Amorphous Carbon rises to one of its greatest uses. Its friendly electrons are happy to exchange with numerous contaminants that come its way, bonding with contaminants and allowing H2O to pass through unheeded….. making it an excellent form for filtration.
The most common types of filtration on the market today use GRANULAR CARBON which is natural occurring carbon in a granular (or rocky-type) form. Usually loose-fitting and, without compaction. Although, this is often one of the least expensive uses, it does not always provide the best filtration by itself. This is because it reacts with the layer of water that reaches each carbon granule, but as there are spaces between each carbon granule, water & contaminants often flow around and though the spaces without interaction, thus passing through the filter without capture. Granular carbon filters usually range from 25 to 100 micron ratings, therefore anything smaller often passes directly through the filter. Example, a human hair is generally 30 to 70 micron, so could in fact, pass through a granular carbon filter. This is not to say that granular carbon is bad, quite the contrary! It does an excellent job on absorbing contaminants that it comes in contact with. Key is that it has to come in direct contact with the contaminant to be removed and with the spaces between granules; it is not a complete filtration system.
The best filtration methods often employ more than one filtration method to cover all of the bases and provide a higher degree of filtration. There are two basic ways to filter something, first to create a PHYSICAL BARRIER – to block contaminants from passing through and/or, CHEMICAL BONDING - to pass the water through an active material to bond with the contaminants, and remove them from the water.
PHYSICAL BARRIER: A physical barrier is pretty simple to understand, the smaller the pore size (usually measured in [µ] microns) the more it will capture, but the slower the water will pass, unless pressure is used to help speed up the process. Depending on the type and cost of a filter, multiple types of materials are used to create the Physical Barrier including micro mesh, membranes, and carbon itself. Just remember the quality of the filtration is linked to the pore size…..thus, Higher micron value- capture less! Lower micron value- capture more!
CHEMICAL BONDING: Remember that Carbon is a friendly element! So it enjoys meeting others and combining or bonding. This usually occurs in two different ways (which sound very much alike!).
ABSORBTION - where Carbon absorbs the contaminant into its structure and holds it close.
ADSORBTION – where Carbon bonds externally to the contaminant as it passes by locking it to itself. This occurs via Ion Exchange with the contaminant……remember, it’s friendly!)
For many of our CLEAR2O® filters, we use SOLID CARBON BLOCK as our Carbon form of choice…..made from compressed carbon powder, and formed into a cylinder. It provides the best of all three of Carbon’s amazing capabilities. Many of our filters are rated at Less than One Micron, which does not have the gaps associated with Granular Carbon and allows a much higher Physical Barrier. The total Carbon used is also much higher which gives more surface area in which to bond to contaminants with higher effectiveness. To insure quick filtration, we usually use water pressure to help speed up the process.
So as you shop for water filters, keep this in mind…….not all filters are the same! If you read the label and they do not list the Micron level, they do not want you to know…..! If so, you may want to consider what’s getting through to your glass.