The importance of clean water (and the lack of it, especially in municipal water supplies) continues to garner national attention. The Flint water system debacle highlights the problem: our nation’s water supplies are compromised—some egregiously, most, seriously.
Flint was the proverbial tip of the iceberg.1 According to Scientific American, the problem of lead contamination that Flint highlighted for the nation was far from an “aberration,” with “nearly 3,000 areas with recently recorded lead poisoning rates at least double those in Flint during the peak of that city’s contamination crisis”; in over a thousand communities, the rate of elevated blood tests has been shown to be at least four times higher than in Flint.2 “Poisoned places” described by Scientific American include a town on the Allegheny River in Pennsylvania (high lead levels in 36 percent of children tested), a “zip code on Goat Island, Texas, where a quarter of tests showed poisoning” and “pockets of Baltimore, Cleveland and Philadelphia, where…the rate of elevated tests over the last decade was 40-50 percent.”2
Moreover, lead is just one very problematic contaminant. Water supplies also face issues with at least three dozen or so other contaminants, including other heavy metals, industrial waste chemicals like perfluorooctanoic acid (PFOA) (see my cookware article3) and more. In addition, almost all municipal water utilities disinfect with chlorine4 or chloramines,5 leaving our water full of dangerous chlorine byproducts.
Seventy-five percent of Americans on community water systems consume water to which toxic fluoride chemicals have been added.6 Fluoride’s presence in our drinking water is unnecessary for its stated purpose (prevention of tooth decay),7 but also poses a real danger to our health and the health of our children.8
These problems with municipal water systems have helped propel several commercial responses, including the unsustainable, costly and wasteful bottled water industry; reusable water bottles; and water filtration. Although the bottled water business has thus far outpaced water filtration as a response, it is important to point out that water filters are both an important and affordable way to deal with our nation’s water woes, especially compared to bottled water. Many water filtration systems bring consumers significantly improved water for under ten cents a gallon. Bottled water, which is often no different from nor any better than tap water, does it for ten to fifty times that cost!
Not all water filters are created equal, however. Even more importantly, specific situations sometimes require specific filtration solutions. To put it another way, there is no perfect one-size-fits-all water filtration system for everyone. Water quality and contamination levels vary greatly. The best system is the one that is tailored to the specific challenges and needs at hand.
This is one reason why testing your water is important. As I constantly say during homestead and farm consults, “Until you test, it’s just a guess!”—and guessing generally turns out to be far more expensive than testing. (For more information about water testing, see “Which filter should I choose?” below and check out my 2014 Wise Traditions article on water testing.9)
FILTERS VERSUS PURIFIERS
Many people use the terms “filtration” and “purification” interchangeably. Technically, the two terms are not interchangeable, but some systems accomplish both functions. A water filter is generally designed to remove a portion of contaminants, some at a high rate, including protozoa and bacteria. A water purifier will remove 90 percent or more of all contaminants in water, including viruses. This viral component is especially important in some situations, such as when traveling abroad or in remote areas where you will make use of water sources of unknown purity. A water purifier is almost always superior to a water filter, but on occasion, a system that is rated to purify water may still leave behind some dangerous contaminants.
In considering the major types of water filtration and purification systems and how they compare, many consumers focus on the external aspects, such as the location of the water filter—countertop, under the sink, inline or the like—but the location of a filter matters far less than its internal characteristics and its effectiveness. Here, I want to focus on the materials and methods of five main types of water filters, rather than on more superficial considerations.
This type of system uses a high-carbon medium to capture contaminants. These filters are primarily or only carbon-based, but other types of filters may also feature a carbon medium component. The porous structure of the carbon substrate traps chemicals and other contaminants. Over time, the carbon medium “fills up” and needs to be replaced. Systems come in both gravity-powered models (such as Brita) or inline (such as Multipure). Some systems have add-ons to deal with fluoride.
Some carbon-based filters use activated carbon instead of plain carbon mediums. Activated carbon has been treated to increase its porosity. To explain just how porous activated carbon is, note that one gram can have a surface area of over three thousand square meters, or thirty-two thousand square feet!10 So, there are a lot of places for pollutants to get trapped in even a small amount of activated carbon, increasing this type of filter’s effectiveness.
In fact, carbon-based filters vary considerably in effectiveness. Some of the most popular water filters on the market (like the Brita or those found on many refrigerators) don’t actually filter much. They are generally just very basic carbon filters, removing some chlorine and chlorine byproducts, and that is about it. The vast majority of low-cost or appliance-based water filtration systems will leave the more problematic water contaminants—lead, industrial chemicals and the like—mostly or even completely untouched. This is changing to some extent because of consumer concerns after incidents like Flint, but older models with older filter technology should not be trusted to deliver truly clean water.
Reverse osmosis (RO) is one of the most well-known water filtration options. In a nutshell, it uses a membrane to capture contaminants, coupled with pressure to force the water through the membrane. The process suffers from efficiency issues, however, with some of the systems creating about three gallons of waste water for each gallon of filtered water they produce. Some newer RO systems have reduced the ratio to one to one.
Most water contaminants are quite large, especially compared to water molecules. They are so large that the use of materials with an incredibly small pore size and a large, maze-like structure allows the medium to trap everything from bacteria to lead. This is how ceramic filters work. Many ceramic filters also incorporate silver or a similar bacteriostatic agent to keep pathogens from colonizing the filter medium. The main material used for most ceramic filters appears to be diatomaceous earth, which contains primarily silica.
Ceramic units have one feature that is both a benefit and a drawback—the outer filter surface needs regular cleaning to remove built-up surface contaminants. This means the filter often lasts longer than other types, but it also requires that you deal with a surface possibly heavily covered in pathogens (and whatever else the filter collects from your water). So exercise caution when cleaning a ceramic filter!
By itself, a ceramic filter does little to deal with chlorine and some other problematic compounds. As a result, many also contain a carbon core and fall under the next category: multi-medium filters.
Multi-medium filters (such as New Wave Enviro and Berkey) go beyond just using carbon or ceramic. Instead, such systems use layered mediums of different materials such as micron pads and carbon substrates—generally in a particular, purposeful order—with the aim of filtering water and achieving other benefits, such as altering the water’s pH or adding minerals back into the water. Given that some use proprietary technology, there is no easy way to evaluate all the possible arrangements of multi-medium filters or to be 100 percent sure what these systems employ and how they work.
A few systems opt to use a number of different approaches to deliver clean water. Many are similar to multi-medium filters—just substantially upgraded! For example, the Radiant Life water filter involves fourteen stages of filtration, purification, sterilization, restructuring, reprogramming and remineralizing. These processes rely on a sediment prefilter, carbon pre- and post-filtration, a reverse osmosis membrane, a mixed bed de-ionization system, ultraviolet light and other features.11
COMPARING LAB TEST RESULTS ACROSS FILTERS
Almost all major filter brands have independent test results showing various chemical reduction levels. However, it is very important to note that because different labs use different tests, equipment and testing protocols, comparing test results can pose significant problems. Ideally, a single lab at some point will test a wide number of systems and contaminants so that all the systems are tested under the same conditions. Until then, while the available tests are helpful, they should not be viewed as definitive.
For an example, take fluoride. If a lab tests a filter’s ability to remove fluoride but starts at twenty parts per million (ppm), while a second lab tests fluoride removal starting at ten ppm, then one filter has double the amount of fluoride to remove. If the first test then documents removal of twelve ppm, and the second filter removes eight ppm, achieving a 60 percent and 80 percent reduction, respectively, any comparison between the two will be misleading. The second filter might have tied with the first if it, too, had removed twenty ppm.
Other variables, such as water pressure or flow rate, may also be different between labs. Unless the various labs are all using the same testing set-up for all the tests—which is unlikely given how many contaminants each lab is testing for—comparing results may be like comparing apples and oranges (or perhaps oranges and minneolas)! In other words, close—but not quite the same.
With that said, Marge Sweigart of The Safe Healthy Home website compiled a chart of the test results for six major gravity filter brands (Berkey, Propur, Alexapure, AquaCera, AquaRain, Zen Water).12 The lab results were collected from the information that the various companies posted to their websites after having independent testing performed on their filters. Table 1 lists the contaminants reduced by some or all of the filters during the tests. (The specific results are available at thesafehealthyhome.com/best-countertop-gravity-water-filter-systems-review/. A result of 75 percent would mean that the filter removed 75 percent of the contaminant, leaving 25 percent after filtration.)
In this comparison, one filter looked like it was worse at removing glyphosate than the other systems, but this result may not tell the whole story. As Mike Adams of Natural News and CWC Labs explains, specific characteristics of the notorious glyphosate molecule make it challenging to produce accurate and reproducible test results and require “unique, complex chemistry far beyond the typical…chemistry used to detect [other] pesticides or common contaminants.”13 These same features can also make it difficult to remove glyphosate from water.14 Having perfected a testing method, Adams and his mass spectrometry lab recently performed their own independent tests on the ability of selected countertop pitchers and larger gravity filters to remove glyphosate, and, importantly, they used the exact same methodology and equipment across the eleven brands. Their tests found some of the filters to be “far more effective than…predicted,” including 100 percent removal of glyphosate in several instances.13
WHICH FILTER SHOULD I CHOOSE?
In choosing a water filter, there are a number of issues that you may wish to take into account. First, consider your water source—is it municipal water, from a well or spring, or rainwater? As Table 2 shows, each of the three main sources of water is prone to particular risks.
Next, test your water. If you are on municipal water, do your own testing and also request copies of the water system operator’s test results (if they do not already publicly post the full test results). You will want both sets of results because a lot can happen en route from the water treatment plant to your home tap, including problems associated with old pipes and all sorts of other issues. It is important to know what kind of water piping your house uses and whether it poses any risks. Modern homes mainly use PVC pipes or PEX tubing; to my knowledge, neither of these poses any significant dangers that a standard water filter will not substantially mitigate. However, some older homes may have pipes that contain heavy metal or other risks that are worth checking.
If you are on well or spring water, ask your local health or other offices whether there are any county- or area-wide testing results available for well or groundwater. Ask your neighbors whether they have tested their water as well. This can help give context and additional insight into your test results.
Third, consider whether you have particular health problems or genetic predispositions that might make you more susceptible to some contaminants. If you have a thyroid condition, for instance, you may want to prioritize a filter (or add-on) that is highly effective at removing fluoride.15 Some water filtration systems also use add-ons to deal with pathogens and possible contamination, ranging from ultraviolet light, iodine, hydrogen peroxide and a host of other approaches. My article on pool water filtration systems explores a number of these in detail, and I encourage you to check it out.16
MAKING IT PRACTICAL
In an ideal world, we would all be able to afford and have access to 100 percent pure water and food. In the real world, however, many of us have budgetary constraints and time and money trade-offs that we have to consider. (Do I purchase pastured chicken or do I invest in a whole-house water filter?) Hopefully, the information in this article can help you sort out where you most need to allocate the resources you have to get the greatest benefit for you and your family. Ideally, with testing results in hand and an awareness of your specific health concerns, you will be able to build a system around your actual challenges and needs.
At the same time, don’t let analysis lead to paralysis. If you can’t decide what to do, just get an affordable basic filter. Any good-quality system in the seventy-five to three-hundred-dollar range will provide substantial benefits, removing anywhere from 75 to 90 percent or more of a wide range of common water contaminants. Table 3 compares the cost per gallon for a handful of popular models. As the table shows, the cost per gallon can vary substantially, and it doesn’t always directly link to performance! For example, the Brita filters that accomplish very little in the way of meaningful filtration cost about two to four times more per gallon than other far more effective brands.
At the end of the day, any good low-cost filter is better than no filter. Also, filtered water is almost always going to be better than bottled water, both in terms of cost and quality. However, skip the countertop pitcher or similar filters that do little to provide any real improvement over standard tap water.
With any home, I always recommend running out your tap for a minute or so in the morning to cycle the standing water out of the system. If your water filter is on a bypass, this can help protect it from sediment or any other build-up or precipitation that formed or settled in the lines overnight.
With rainwater collection, it is ideal to have a “preflush”—a set-up that diverts the first ten to twenty gallons of rainwater, which will be the most contaminated and dirtiest water the roof produces during rain—away from your storage tanks. This will increase filter life and performance substantially.
LAZINESS IS NOT AN OPTION
Any system that relies on a filter poses one particular danger to users: backwash after the medium reaches capacity. Filter mediums can only absorb so much contamination. Once they reach saturation, they may not only stop filtering incoming water, but backwash the many, many months of concentrated, built-up contamination back into your water! Thus, it is very important to change your filter cartridges or medium regularly based on its rated capacity and your water usage. Basically, the more water you use, the sooner you should replace your filter, regardless of any monthly or annual guidelines the manufacturer gives. Some companies make this easy by allowing you to sign up for automated reminders (mail, text or email) or even automated shipment of new filters on a set schedule. No matter what reminder system you choose, it is very important that you find a way to ensure that you don’t use your filter past its capacity.
Depending on your water source, some systems either use or will benefit from a prefilter. Generally, a prefilter doesn’t so much remove contaminants that are dangerous to your health as it takes care of stuff that is dangerous to your filter’s health and performance. In setting up rainwater catchment systems, for example, prefiltration to remove dust, dirt and large debris is a must and will help protect and extend the life of the next stage of filtration substantially. Without a prefilter, the main filtration system will underperform (because it is dealing with particulate matter and other incoming debris), and the system’s rated life will be greatly reduced. This is just one example of why figuring out exactly what filtration you need for the water system you have is vital.
- Teller M. Lead in the water: Flint’s cautionary tale. Wise Traditions 2016;17(1):42-6.
- Pell MB, Schneyer J. Thousands of U.S. areas afflicted with lead poisoning beyond Flint’s: the Michigan city doesn’t even rank among the most dangerous lead hotspots in America. Scientific American, n.d. https://www.scientificamerican.com/article/ thousands-of-u-s-areas-afflicted-with-lead-poisoning-beyond-flints/.
- Moody J. Cookware keeps getting safer, but it’s still caveat emptor! Wise Traditions 2018;19(4):73-6.
- Disinfection with chlorine. https://www.cdc.gov/healthywater/drinking/public/chlorine-disinfection.html.
- Chloramines in drinking water. https://www.epa.gov/dwreginfo/chloramines-drinking-water.
- National water fluoridation statistics. https://www.cdc.gov/fluoridation/statistics/2014stats. htm.
- Tooth decay: topical vs. systemic effects. http://fluoridealert.org/issues/caries/topical_systemic/.
- Bashash M, Thomas D, Hu H, et al. Prenatal fluoride exposure and cognitive outcomes in children at 4 and 6-12 years of age in Mexico. Environ Health Perspect 2017;125(9):097017.
- Moody J. Water, water, everywhere, but is it safe to drink? Wise Traditions 2014;15(4):68- 71.
- Activated carbon. https://en.wikipedia.org/wiki/Activated_carbon.
- Countertop gravity water filters: which is best? 2019 edition. https://thesafehealthyhome. com/best-countertop-gravity-water-filter-systems-review/.
- Adams M. Water filter glyphosate removal lab test results released by Natural News—see the full video here. Glyphosate.news, Feb. 12, 2019.
- Adams M. Mike Adams/CWC Labs announces glyphosate lab testing of popular water filters…see exclusive video here. Natural News, Feb. 3, 2019.
- Peckham S, Lowery D, Spencer S. Are fluoride levels in drinking water associated with hypothyroidism prevalence in England? A large observational study of GP practice data and fluoride levels in drinking water. J Epidemiol Community Health 2015;69(7):619-24.
- Moody J. Chlorine-free swimming pools. Wise Traditions 2016;17(4):59-61.
This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly journal of the Weston A. Price Foundation, Spring 2019