In our years of working in water filtration, we often run into people unsure as to some of the major differences in home water filtration systems. We hope this guide may help highlight some of the key differences in the basic technologies available to empower buyers to make the best decision based on their specific water needs.
Understanding Your Water Filter Needs
The first question you have to ask yourself is what purpose do you want your filter to serve? Are you looking for better tasting water? Do you want to keep your family safe from consuming tasteless, odorless contaminants in your drinking water? Do you want the filter to sit in a refrigerator or sit on a counter-top? Is the filtered water for cooking and cleaning or just for drinking?
Budget is another factor in the selection process with modest pitchers starting at $20 up to comprehensive, installed units costing $2,000 and beyond. Replacement filters are another cost and deciding factor as any filter that is actively removing contaminants will eventually exhaust and require replacement. Lower-end models will require replacement every 30-40 gallons which is sometimes less than a month of use and range in cost from $5-20. Alternatively, solid carbon block filters can last up to thousands of gallons depending on size and range in cost from $40 to $500. How frequently you want to be buying and replacing your filter is both a decision of cost and convenience
Originating in restaurants and hospitality applications that required extensive, high volume water purification, under-the-sink (UTS) systems eventually began trickling into residential use.
The greatest strength of these systems stems from their access to pressurized water supply. They utilize a thicker filter that gravity alone could not push water through. However, 60 psi of pressure offers plenty of power to push the water through the heavy-duty filter and remove any contaminants that may exist. These systems often incorporate multiple stages to provide a variety of pre-, post, and specialty-filters as desired.
However, space under the sink is often at a premium and and these lavish systems are quickly viewed as bulky. Filter replacement can lead to a craze of unpacking and repacking for the plumber to hop back and replace the clogged cartridges.
And while these systems often offer premium water quality, they also come at a great cost. Not are they expensive to purchase, but they require professional installation including drilling into the sink or counter top to install a spigot and routine professional inspections which drive up their high price tag.
A subset of UTS filters is a technology called Reverse Osmosis. We tend to steer away from Reverse Osmosis (RO) in most instances for 2 main reasons: they waste more "dirty" water than they generate and they are unable to differentiate healthy minerals from harmful contaminants leaving the outbound water completely bare of potential nutrients.
The science behind RO requires approximately 4 gallons of water to be wasted for every 1 gallon of "clean" water produced. This is unacceptable to us as we view water as such a precious natural resource. How could we feel good about encouraging healthy water consumption if it meant wasting 4 times that amount in the process.
Additionally, while Reverse Osmosis is effective at removing contaminants, it can only do so by removing all non-water components from the water. This isn't ideal as there are many essential nutrients to the human body that we consume partially through our drinking water.
If UTS was the only available option to acquiring safe drinking water, we'd be more apt to recommend it. However because there are healthier, more environmentally-conscious options, we don't view under-the-sink systems as the best homemwater filter option.
Granular Carbon Pitcher Filter
Granular water filters are by far the most common on today's market. "Brita" is almost synonymous for home water pitcher and the most popular granular filter.
These types of filters are made of crushed carbon media that chemically adsorb chlorine as well as other contaminants that give water a bad flavor or odor. Wait a minute, did you just say "adsorb"? Didn't you mean "absorb"? Well, there's a difference. Sponges "absorb" meaning they bring the water into their core. Activated carbon adsorbs similar to the word adhere meaning it's outer shell has activation sites where it chemically bonds to specific elements that pass by.
The media is crushed into particles large enough to sit in a screened container and allow water to pass through it without any carbon pieces passing through as well. The larger particle size leads to a faster flow and therefore lesser contact time with the reduction media. When there are fewer paths for water to take, channeling is more common in which the majority of the water attracts to the option of least resilience (highest speed) which is counteractive to the desired outcome. For a hypothetical example, with 10 available paths and 80% of the water passing through 2 of the 10, it is easy to see that the reduction sites on those paths will quickly get used up warranting the entire filter useless. Ideally, let's assume 50 paths, even in the instance of channeling in which 10 paths experience a majority of the water traffic, the filter's lifespan significantly elongates. Overall small surface area, resulting in fewer reduction sites, translates to rapid filter exhaustion (all the sites are used up) requiring frequent filter replacement.
Granular filters have larger chunks of carbon as well as more space between particles which increases the speed and shortens the path that the water takes through the filter which both reduce the time that the water spends in contact with the adsorption media.
The low surface area and short contact time limits the capability of the filter. Manufacturers often target a higher reduction claim of fewer contaminants like Chlorine, taste and odor due to this limitation rather than making the attempt to reduce the numerous possible contaminants highlighted by the EPA.
Solid Carbon Block Counter-Top Filter
A solid carbon block filter utilizes the same adsorption technology of activated carbon-based media although it utilizes a unique manufacturing process to overcome the limitations of granular carbon filtration highlighted above. By taking on a solid physical shape that forces water to slowly pass through a maze of small crevices that wind back and forth causes a much longer path for the water to pass through as well as many more channels which further combats water channeling. The solid nature of the block provides an infrastructure in which the media is embedded allowing it to be more finely crushed without concern of passing through the bottom threshold along with the filtered water molecules. The smaller granule size increases adsorption efficiency without simply increasing the amount of media which helps keep the material cost low while increasing performance. These 2 characteristics of increased contact time and number of reduction sites unique to the solid carbon block versus the granular media result in higher filter performance and longer filter lifespan.
The difference between granular versus solid block filters is similar to these 2 labyrinth mazes (left represents granular; right represents solid block). Solid carbon block filters increase both the amount of time that the water spends in the filter as well as allows for a greater number of reduction sites which increases overall filter performance.
Here is an example to show how surface area impacts filter lifespan. Let's assume that 2 filters didn't channel the majority of the water through certain "highways" of least resistance and all areas of the filter were equally passed through. A granular carbon filter has 100 parking spots and a solid block filter has 1000 spots for contaminants to be trapped and every pitcher of water has 10 contaminants. The first pitcher can used 10 times before it becomes exhausted and essentially useless, while the second filter can be used 100 times. Ideally, a filter would like to have as many possible reduction sites as possible to increase its lifespan.
The reason many pitcher filter companies do not use solid block carbon filters is it costs more to manufacture and filtration speeds are often slower. Also, pitcher filters have historically used granular media and with limited consumer knowledge of their shortcomings, they are perceived to work "just fine" which does not incentivize manufacturers to increase their quality.
In order to combat these 2 reservations to solid block filters, the leading manufacturer of solid block filters makes a massive water station that sits on a counter-top and filters up to 6 gallons of water at a time. The benefit is obviously someone isn't typically seeking 6 gallons at once so after the apparatus is filled, it can filter over a long period of time without people sitting and waiting for the filtered water to become available. This also reduces the amount of fill-ups which is attractive to some users.
The most obvious downside to these systems is they are huge and often deemed unattractive in the many kitchens which have become centerpieces to entertainment and social interaction. These giant chunks of steel are not what most decorators would prescribe to spruce up a living area. Yet, we are in a struggle between aesthetics and function as the technology in solid block filters is obviously far superior to the traditional granular media in pitcher filter options. If left with no other option, we completely understand why people decide to put their families health ahead of their household decor.
However, these massive water silos are no longer the only offering of solid carbon block water filters.
Solid Carbon Block Pitcher Filter
REVIVAL water filters incorporate the same solid carbon block technology on a smaller scale to fit into our mini and large water pitcher.
REVIVAL utilizes a proprietary blend of carbon media with a improved reduction capability to increase performance at a faster flow rate. Paired with our distinct knowledge of carbon block manufacturing, we were able to adjust the porosity to make the water flow at speeds comparable to common granular filters. REVIVAL filters are capable of removing up to 99.99% of over 70 contaminants for over 150 gallons of drinking water. (up to 5 times longer than the competition.) However, we didn't stop there...
Realizing that there were so many small preferences in water filters and that once a consumer had the knowledge to identify their water needs, they'd want something tailored specifically for them, we also developed a bacteria filter with a smaller pore size (it needs to be to trap those microorganisms), an alkaline filter that increases the alkalinity of the outbound water (many potential health benefits), and an emergency Radiation filter that removes 99.99% of radioactive particles.
While solid block filters require a more extensive and expensive manufacturing process, REVIVAL filters offer such a long lifespan that the dollar value ($/gallon) is competitive with all the leading granular filters while the performance value far exceeds the competition. We believe that with a bit more consumer education, many would choose a slightly slower filter that will deliver significantly higher filtration performance for the same long-term price. Then the real decision becomes which pitcher and filter is right for you?
Mini vs. Large Pitcher
REVIVAL offers 2 pitchers sizes designed specifically for different user environments. The Large pitcher has an 8 cup reservoir to filter greater volumes of water with 1 fill-up and utilizes a larger filter to last up to 150 gallons before needing replacement. This is by far, the longest lasting pitcher filter on the market. The Large pitcher is suited for high volume use in an environment with the space for a full-sized water pitcher either in the refrigerator or sitting on the counter-top.
Both pitchers are made of a BPA-free, durable, stylishly clear polymer and include the easy-fill, drop-down door for ergonomic, one-handed filling.
Ultra, Rural, Health, or Rad?
Each REVIVAL filter was specifically designed for a unique user and purpose.
The ULTRA filter includes our flagship technology that every other filter incorporates and builds off of. Our proprietary media blend was specifically selected to target and eliminate as many contaminants to as great a degree as possible. Our test data speaks for itself with extreme contaminant reduction spanning Disinfectants and their byproducts (Trihalomethanes, Chloramines, Chlorine), Inorganics/Heavy Metals (Asbestos, Chromium (6), Copper, Fluoride, Lead, Mercury, Nitrate, Nitrite, ), and VOCs (Benzene, Chlorobenzene, Polychlorinated buphenyls, Xylenes), Pesticides, and Pharmaceuticals.
The RURAL filter adds a 99.99% microorganism reduction component to the Ultra technology for users with concerns of pathogens in their drinking water. These users often live off of non-regulated water and either self-treat or have reason to suspect that their source water has been contaminated.
The HEALTH filter combines the our premium filtration technology with proprietary media to raise the alkalinity of the water up to 9.5 as well as filter the water. The convenience, cost savings, environmental impact, and knowing the water has been filtered as well as alkaline all support switching from drinking bottled alkaline water to making your own with the REVIVAL Health filter. Why not be the healthiest you can be with the best of filtration and alkalinity in a single water filter.
The RAD filter provides serious protection in a time of potential crisis by including proprietary media who's role is to remove 99.99% of radionuclides that could become present in our drinking water in the instance of a natural disaster or terror attack. It's a filter you hope you never need but will save your life in the instance that you do. Compatible with the large filter, it never hurts to be prepared with a REVIVAL RAD filter (or a couple), just in case.
REVIVAL delivers the greatest filter performance in the most convenient form at the best value while also providing custom options to cater to specific water needs.
CLEAN WATER, YOUR WAY!