Water is everywhere in the Adirondack backcountry; swinging a dead blackfly is impossible without getting wet. Unfortunately, it is not clear how much of this water is safe to drink. For that reason, most backcountry enthusiasts treat their water, thus avoiding the possibility of bringing home a unfriendly aquatic pathogen surprise that could unwrap itself as a putrid rear-end explosion days after returning home.

There are many different ways of treating questionable water sources, the most common being boiling, adding a chemical or filtering it through a permeable membrane. These days most backcountry explorers go the filter route, as it is often the cheapest, most practical and convenient way to ensure safe drinking water.

One water filter that combines the characteristics of both chemical treatment and a membrane in an unconventional way is the PurifiCup. This filter with the odd-sounding name differs from most other filters with its world-patented silver membrane design, which the manufacturer claims eliminates up to 99.99% of all bacteria and parasites, including some 600 different types of vicious and nasty backcountry critters.

PurifiCup goes beyond the needs of the Adirondack backcountry with its exclusive 3-stage filter technology that removes more than just the usual biological pathogens. The first stage, with its ion exchange resin, removes numerous heavy metals (e.g. lead, copper, cadmium, mercury, etc.) plus calcareous substances (e.g. magnesium and calcium ions). Next, an activated carbon component removes chlorine and other organic odorous substances, such as trihalomethane (THMs), organic solvents and pesticides. Finally, the silver membrane eliminates the many annoying biological pests, including E. coli, giardia
and Cryptosporidium.

For those interested in all the nit-picky details, check out the PurifiCup website, which contains a plethora of information on its unique technology, as well as numerous reports on its efficacy at removing biological pathogens and other dangerous substances from natural water sources.

The PurifiCup comes in two different versions: the Natural Water Series and the Portable Water Series. The Natural Water Series purifier comes in either green or purple color, while the Portable one is available only in orange. The Natural Water Series is the backcountry filter, specifically designed for the natural water sources commonly found in the remote areas of the Adirondacks.

The PurifiCup is well made and compact, consisting of three main parts: an outer and inner cup, and the filter housing. The two cups are 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 one, 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 PurifiCup has a capacity of 11 gallons, which is approximately 150 cups of water. A counter, functioning similarly to a bicycle combination lock, provides the convenience of keeping track of the filter’s production. The instructions recommend replacing the filter every four months, whether that means four months of frequent use or time spent in the closet during the winter months remains unclear.

The PurifiCup is engineered with a number of different types of water bottles in mind. A small threaded attachment on the base of the filter allows for attaching regular soda bottles or Platypus collapsible water bottles. Unfortunately, water bottles without a broad base prove too unstable since the full weight of the water is on top of the filter in the outer cup. Although the filter’s base is large enough to fit a standard-sized Nalgene bottle, it lacks any threading so take care not to knock it over with dirty water within the outer cup.

The instructions for the filter are largely poorly written and scant on details. The grammar reads as if a non-English speaker wrote them, with articles missing or present where unnecessary and plurals often absent. Although the filter has only a few parts, some assembly instructions would be helpful if included, as would be some details about troubleshooting.

Although not nearly enough to qualify as television drug commercial, the PurifiCup instructions state a number of warnings. This filter is not appropriate for children or people with immune system disability. Also, because a small amount of potassium is introduced into the water, people with kidney disease or with potassium limited diets should consult their physician before use.

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.

The stability of the filter is a concern, especially when flat, hard surfaces are at a premium. 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. Although a valve attaches the outer cup to the filter, the inner cup remains unattached as there are no threads provided on the bottom of the filter casing.

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. For day hikers looking for water on the go, instead of filtering larger amount at a time, this is not a major concern.

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. Anyone concerned about this happening, it would be best not to place the inner cup within the outer cup while in the field.

The PurifiCup’s design makes it cumbersome to use it with a collapsible water bottle, like the Platypus line manufactured by MSR. A threaded outlet on the filter does allow for screwing in a Platypus bottle, but the entire filter has to be held up 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.

Recently, I took the PurifiCup out for a test drive in the Adirondack backcountry, when I reunited with the Pepperbox Wilderness after a two-year absence due to a mysterious knee injury. The Adirondacks seem like the ideal place to put a filter through its paces, where the water can run from tannin-infested beaver swill to crystal-clear mountain streams.

Despite choosing the outlet of Deer Pond, where it runs through a relatively young beaver meadow, the water proved less than challenging as it seemed as clear and colorless before going through the filter as it did afterwards. The water had but a hint of an aftertaste, whether due to the filter or from natural sources was uncertain.

The worked quickly, as I drank down at least three cups while waiting for my usual gravity filter to produce a couple liters. Two previous PurifiCup experiences resulted in a slower water flow over time, but this time I noticed little difference. Unfortunately, while filtering the fourth cup, I noticed water pooling between the filter and the filter housing.

It appears the filter housing had somehow become unscrewed enough to allow dirty water to circumvent going through the filter element. The lack of rubber seals within the filter housing may have allowed the dirty water to contaminate the filtered water quaffed down earlier. If I end up with giardiasis, I will share this unpleasant experience here at the Almanack in the future.

Despite some hiccups, 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.

The PurifiCup normally retails for a reasonable $60, with replacement filters at $15. It is available from Amazon, as well as some other retailers.

Disclosure: PurifiCup provided a PurifiCup Natural Water Series in green free of charge for the purpose of this review.

Photo: PurifiCup, Natural Water Series by PurifiCup and PurifiCup in action by Dan Crane.