How to Choose a Water Filter Part 4 of 10: Taste & Odor

by wfnblog on March 4, 2011


Confused CharacterAs we continue this series How to Choose a Water Filter, we’ve already dealt with sediment filters and will now delve into the taste & odor category. So, what do we mean by a taste & odor (hereafter T & O) filter? If you slot your water issue into the T & O category this means you are not worried about “high level” contaminants like heavy metals, and VOC’s etc… (high level contaminants will be covered when we are done with the T & O category). In a nutshell, you simply want your water to taste and smell better.

Tasteless, odorless water is rare because water is the universal solvent, meaning it dissolves nearly everything it touches (think microscopically). As a result it absorbs various substances which affect T & O. The good news is most T & O issues can be cared for with an activated carbon filter. Activated carbon, also known as carbon, charcoal, and activated charcoal is an amazing substance with a massive surface area. This surface area makes it ideal for capturing contaminants. For details concerning how carbon works and what it removes from water, see these documents from the Water Quality Association: How Carbon Works & What Does Carbon Remove From Water. Carbon for water filtration is available from two primary sources, bituminous coal (think coal in the ground from decayed plants and trees) and coconut shells which are charred into carbon (no, they don’t make your water taste like coconut). There is also carbon made from bamboo which is growing in popularity because of its astonishingly fast rate of growth which makes it more sustainable. However, it is not commonly available at this time, but watch for it going forward. When we get to the High Level Contaminants installment of this series we will go into greater detail about the different types of carbon, i.e. granular, block, catalyzed etc… and their unique performance characteristics.

So, let’s get down to business. You need to decide if you want to address your T & O issue at the whole house level, or only at specific points of use. Your decision will depend greatly on the specific problem. Some odor problems make bathing and showering unpleasant and will probably lead you to a whole house solution, though shower filters are available, while other T & O issues are only noticeable when drinking the water, so a point of use system would be an option. In either case you will likely end up with some kind of carbon filter. If you go with a whole house water filter be sure the system is actually large enough for a whole house application. Refer back to part 2 for information on size issues. There are automatic backwashing whole house carbon filters that require very little maintenance, and there are filter cartridge based systems for both whole house and point of use, but remember your issue is merely taste and odor, so you don’t need to worry about NSF standard 53 or long lists of contaminants removed; you just need a carbon filter. I’m not trying to oversimplify it when I say that nearly any carbon filter will satisfy your needs for T & O improvement.

Unfortunately many of you will have both a sediment and a T & O issue. If so, you need to deal with those issues separately. Use a sediment pre-filter followed by your carbon filter. You’re probably wondering why you can’t simply use a 5 micron or 1 micron carbon filter and be done with it all at once. It’s not that carbon filters won’t capture sediment, they will. It’s that they will clog much faster than a sediment filter and are usually 3-5 times more expensive. So, the money you spend for a separate sediment filter will pay for itself over time as you get the full life and usefulness out of each carbon filter. Carbon filters are great at removing many contaminants, but they are not best suited to deal with medium to heavy sediment issues. Since you’re going to the work and expense of installing a filter system, you may as well do it right from the start and you won’t regret it.

There are, of course, many different causes for various types of T & O issues, but one of the most common is H2S or Hydrogen Sulfide which is often described as rotten egg odor. Though carbon water filters will remove H2S, they will only do so for a very short time before the filter becomes quickly exhausted. Many people are thrilled to find what appears to be a solution to this stinky problem, only to suffer the disappointment of a filter that wears out very quickly. The whole story is that carbon isn’t really appropriate for H2S reduction. For H2S issues nothing compares to KDF (Kinetic Degradation Fluxion), but that will need to wait because that’s my teaser for the next installment.

I hope you are finding this series informative. WE WOULD LOVE TO HEAR YOUR COMMENTS!!

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