Water is a precious commodity, essential for life; although its importance is often overlooked until it is in short supply. Finding drinkable water while on the trail always remains a challenge, whether hiking in a remote area far from civilization or ambling along through the countryside, never far from a paved road. Since the safety of natural water supplies must remain suspect at all times, it is essential to carry a water filter or purifier to avoid infection of any pathogens.
Water filters and purifiers are widely used to treat questionable water sources while on the go. They typically contain a membrane that physically prevents larger microbial life from getting through and/or involve adding a chemical toxic to both microbes and viruses alike.
Katadyn remains the manufacturing titan of water filters and purifiers, although I primarily use a Sawyer inline filter due to its lightweight and small size. A new kid on the block in the filter/purifier world is the PurifiCup, a self-contained, on-the-go water purifier that goes above and beyond in filtering out more than just dangerous pathogens.
The PurifiCup differs from most conventional filters because of its world-patented design using a silver membrane filter, which the manufacturer claims eliminates up to 99.99% of bacteria and parasites, including some 600 different types of nasty backcountry critters.
One membrane is not enough for the PurifiCup, as it uses an exclusive 3-stage filter technology that removes more than just biological pathogens. First, its ion exchange resin removes many heavy metals (e.g. lead, copper, cadmium, mercury, etc.) plus calcareous substances (e.g. magnesium and calcium ions). Second, an activated carbon component removes chlorine and other organic odorous substances such as THM, organic solvents and pesticides. Finally, the silver membrane eliminates the many pesky biological pests, including E. coli, giardia and Cryptosporidium.
See the PurifiCup website for more information on its unique technology, as well as reports on its efficacy at removing biological pathogens and other dangerous substances from natural water sources.
The PurifiCup is well made and compact. It consists of three main parts: an outer cup, an inner cup and the filter housing, with the two cups constructed out of sturdy 100% food grade plastic, allowing for many years of use. While packed for travel, the inner cup fits inside the outer cup, while the filter screws into the two of them like a top, with two caps sealing off the bottom of both the outer cup and the filter bottom, making a snug and secure container that easily fits into any backpack.
While filtering, the outer cup functions as the reservoir for the dirty water, and sits on top of the filter with the inner cup underneath to capture the filtered water. The outer cup connects to the filter via a valve, while the filter sits loosely on top of the inner cap, which acts as a base for the entire unit.
The sturdy construction and exclusive technology makes the PurifiCup a competent water filtration system for some backcountry adventures. However, the remote backcountry is not where the PurifiCup truly shines. The trail systems that skirt agricultural fields, descend into junk strewn ravines or approaches anywhere near human habitations (for example along the Finger Lakes Trail) is where this water purifier comes into its own, due to its unique technology allowing for the removal of both heavy metals and pesticides.
Unfortunately, I have yet to give the PurifiCup the extreme field-testing that only the Adirondack’s murky, tannin-infested waters can dole out due to a knee injury at the beginning of the warm-weather hiking season last year. Instead, my only practical use of the filter was in my own kitchen, using clean tap water. At first, I found the filter rather slow, but after conferring with the manufacturer and taping the filter vigorously on the kitchen counter to remove trapped air, the water flowed quickly, taking less than a minute to filter 10 ounces.
The lack of a field test is definitely a shortcoming of my experience with the PurifiCup, unfortunate, but beyond my control due to the injury. I plan to take it with me on my Birdathon adventure in the Pepperbox Wilderness this May, as long as health and weather conditions allow. Keep your eyes peeled for another review, complete with a field test, in the Adirondack Almanack during late spring or early summer.
Despite the sturdy construction, interesting and seemingly effective technology, the PurifiCup is not without its shortcomings, especially for backcountry use, and particularly for those few intrepid souls such as myself that spend a significant amount of time off-trail bushwhacking. Note that these are perceived shortcomings, as I stated above I have yet to take the PurifiCup into the backcountry.
The stability of the filter while in use is a primary concern for me. When fully assembled, the PurifiCup stands about 13 inches tall, with the larger outer cup sitting on top of the filter, while both are precariously perched on the inner cup, which acts as a base. Although a valve attaches the outer cup to the filter, the inner cup remains relatively unattached as there are no threads provided on the bottom of the filter casing. Given the outer cup is initially two-thirds filled with water, with the narrower and unattached inner cup acting as a base, the entire operation remains rather unstable. In a bushwhacking circumstance, where flat and stable areas are at a premium, this could be a problem. Without even taking it into the field, I can easily imagine knocking this over many times while setting up my campsite.
Luckily, the filter operates rather quickly, reducing the opportunity to knock it over, although the filtering rate most likely decreases with use. Unfortunately, this points out another shortcoming; the PurifiCup is rather needy, requiring a lot of individual attention. Since it filters only about 10 ounces at a time, it requires many fillings, with the water constantly transferred from the inner cup to a larger receptacle. Given I like to multitask while filtering water (e.g. setting up my tarp, making dinner, watching birds, etc.), this is a major disadvantage over my current Sawyer inline filter filtering system.
As noted by other reviewers, the possibility of drip back from the filter into the “clean” inner cup is a concern in the field after its initial use, when packed up and inside a backpack. The manufacturer could easily remedy this by placing a screw-on cap on the intake of the filter itself though.
The PurifiCup’s design makes it cumbersome to use it with a collapsible water bottle, like the Platypus line manufactured by Cascade Designs. A threaded outlet on the filter does allow for screwing in a Platypus bottle but the entire filter has to be held up (or some sophisticated and imaginative contraption has to be designed to do so) while pouring the water into the outer cup before commencing the filtering. Only an octopus with its eight tentacles would fail to find such a feat a challenging effort, especially when swatting away hordes of hungry black flies, mosquitoes and/or deer flies.
The manufacture’s literature indicates the PurifiCup’s capacity is only 11-12 gallons. This capacity seems on the low side for a backcountry filter, where one may easily go through a gallon in a single hot day. This may force one to filter their drinking water only, requiring packing in more stove fuel for boiling all cooking water. Otherwise, one or more replacement filter cartridges should be carried on longer trips or during very warm weather.
The filter provides a counter, functioning similarly to a bicycle combination lock, for the convenience of keeping track of its production. The instructions recommend replacing the filter every 4 months for best performance. It goes unsaid whether this time is regardless of use, where a filter element could expire while sitting in a closet during the winter months.
Although the PurifiCup is a very well made product, and appears to function adequately, I doubt it will make its way into my backpack for many backcountry adventures. Its instability, size, weight and limited capacity make it insufficient for my usual bushwhacking adventures, especially when compared to the Sawyer inline filter system I typically use now.
However, the PurifiCup is a highly functional, compact and well-made piece of equipment, ideally suited for shorter trips, especially in areas near human dominated landscapes, where the contamination by heavy metals, livestock and chemicals is a major concern. In these areas, this filter probably excels in its ability to provide clean and drinkable water on the go.
For day hiking trips, especially in more civilized area, the PurifiCup is an excellent choice for a portable filter where water on demand is required. Also, it makes an excellent choice for those in the prepper community too, acting as an excellent complement to dried foods from Wise Storage Foods, where it could come in handy during any emergency, such as a natural disaster, nuclear winter or zombie apocalypse. Just make sure you purchase many replacement filter cartridges.
Disclosure: The manufacturer provided a PurifiCup Natural Water Series, in green, free of charge for the purpose of this review.
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