What does a Carbon Filter Really Remove from the Water?

by wfnblog on December 10, 2010


Granular Activated CarbonThe subject of Granular Activated Carbon (GAC) is at times both simple and complicated. This reality stems from the fact that some filters are not using merely GAC, but rather a combination of GAC and special additives that enhance the GAC and improve it’s overall spectrum of contaminant reduction. This is further complicated by the fact that some filters are “certified” to remove specific contaminants by a testing process, usually performed by an independent laboratory. This leaves the uncertified filters looking cheap, worthless, and incapable of reducing any contaminants, because surely a filter would be “certified” if it were worth anything at all. Yet, nothing could be further from the truth!

This begs the question, “What does a GAC filter really remove from the water? The fact is, all GAC, certified or not, will reduce certain contaminants. Many filters do not present a certified list because it is a foregone scientific conclusion that all GAC will definitively reduce certain specific things. The fact of GAC’s ability to reduce certain contaminants has long been established by thorough empirical scientific testing. This is similar to legal precedent that need not be retried over and over in a court of law, because the facts of the case have already been settled once and for all. For example, there is absolutely no reason to certify a GAC filter for Chlorine removal, because it is a fact that, given a certain amount of GAC and a certain flow rate of water through the GAC, it will reduce Chlorine by a certain percentage. This is fact, and there are dozens of other contaminants that are also long ago proven to be reduced by GAC.

We understand your skepticism, which is why we ask you not merely to trust us, but to trust the Water Quality Association (WQA), which exists for exactly this reason. The WQA is the center of gravity in the water purification industry and is a not-for-profit international trade association representing the residential, commercial, industrial, and small community water treatment industry. The WQA provides consumers as well as business owners with solid trustworthy information, like this article titled “What Contaminants Do Activated Carbon Filters Remove From Water? and this excellent article that demystifies the science of “How Carbon Works”.

None of this is meant to suggest that certification and testing are somehow evil, because they do serve a purpose. It is, however, our intention to clear away some misconceptions about non-certified GAC filters. Many people get hung up on the fact that a filter is or isn’t certified and many end up paying more for a certified filter that they didn’t really need simply for fear of buying an uncertified filter. This is just plain unfortunate and unnecessary. Uncertified GAC filters are perfectly capable of reducing certain contaminants. Furthermore they are often significantly less expensive because they do not have the cost of expensive certifications adding to the price tag. They are not perfect for every situation, for example if you need to reduce lead from your water, your going to need a special GAC filter with unique additives for lead reduction, and that filter will require certification to validate that it really does reduce lead. There is no doubt certified filters have their proper place, as do the agencies that perform the certification, but let’s not allow the certification to say more than it really does.

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