Cnoc Vecto and Versa Flow Gravity Water Filtering System is light, efficient, compact

Posted on: June 4, 2019

MSRP: $44.99

Proper water purification is an essential element for any expedition. If you can't stay hydrated on the trek in to your dream climb, or stay healthy while waiting for the weather window in base camp, you might as well kiss that #victory_gram goodbye.

I took the Cnoc (prounced "K'nok") Vecto and Versa Flow Gravity Water Filtering System with me on an expedition to Aconcagua in the Argentine Andes this past austral summer, and later performed more focused field-testing in the foothills of the Sierra Nevada Range in California this spring.


When I first received the Vecto-Versa, I was immediately impressed with how packable and compact the system was. The total weight of the complete package—two 2-liter bladders, the filter and plastic carabiner—is 7.62 ounces and it packs up smaller than a half-liter Nalgene bottle.

Besides the low volume and weight, the Versa boasts an incredibly efficient flow rate and can filter two liters of water in under three minutes, faster if you squeeze.... The fast flow rate is due in part to the hollow fiber technology in the Versa Flow component of the system. Instead of filtering the water through the core of the tubes, the Versa Flow filters through the outside of the tubes. By bending the fibers and increasing the surface area of filtration, it increases the rate of flow.

Mike Gimli Able puts the Cnoc Vecto and Versa Flow Gravity Water Filtering System to the test in the low lands of Aconcagua Provincial Park, Argentina. [Photo] Tad MccreaMike "Gimli" Able puts the Cnoc Vecto and Versa Flow Gravity Water Filtering System to the test in the lowlands of Aconcagua Provincial Park, Argentina. [Photo] Tad Mccrea

While filtering water on the Rio Horcones, we were forced to deal with heavy sediment from the gritty, mineral dense slurry. After filtering six liters of water (read: chocolate milk) we noticed a slight decrease in the speed of flow from the filter; but after back flushing the system with about a half-liter of filtered water, we were able to easily increase the flow again.

In my experience the Versa has a faster flow than the comparable Sawyer Mini, and is also easier to clean. I was surprised by how pure the filtered water both looked and tasted, given that the pre-filtered milkshake wasn't even the slightest bit translucent.

Getting sick while on an expedition might leave you writhing in base camp while your partners are up in the clouds shooting summit selfies. The Versa Flow removes 99.999 percent of all bacteria and protozoan cysts, including all of the heavy hitters such as E. coli, salmonella and giardia. Viruses are another matter because those can get through filters. Luckily we rarely deal with waterborne viruses in the wild places of North America. While on international expeditions, however, I still carry either chemical drops or tabs for situations in which I am genuinely concerned about viruses in the water source. In this case, I would add the purifying agent after filtering the water to remove particulates as well. Boiling the water for at least one minute (3 minutes when at altitudes above 6,562' or 2000m) is another alternative, according to Centers for Disease Control.

The Vecto features an intelligently designed dual opening system. One end of the bladder has a 28mm threaded neck with a cap that mates with the Versa, and the other end has a wide opening that is sealed with a slider to facilitate options for filling and provide easier access for cleaning and drying. Though I appreciated the wide opening, I found that it was difficult to fill with one hand because of the rigidity of the closure materials.

The slider closure system is simple and effective. All you have to do is fold the top lip of the reservoir over itself once before sliding the plastic clip over the folded lip. I tried pretty hard to make this closure leak to no avail. That said, I still probably wouldn't plan to use the Vecto as stored water capacity in my pack for any long period of intense use without locking the slider. I thought it was most useful on the go while squeezing the water from the Vecto through the Versa Flow straight into my water bottle. The unit is so time efficient that it makes sense to carry less water while moving and filter more often if you know you have a water source nearby.

The Vecto bags are made from extremely durable TPU (a BPA-free polyurethane plastic) built to withstand 220 pounds of pressure. The welded seams do not create any hard edges, which traditionally can lead to cracks and leaks. Some other reviews I read on the Vecto referenced a chemical taste and odor upon initial use. Personally I didn't notice anything out of the ordinary and thought that the water tasted not only palatable, but pure.

The included "S Biner" (0.42 oz.) is useful enough, however, I think it makes sense to ditch the non-load-bearing plastic in exchange for a segment of 2mm cord, which is lighter and more versatile. Besides, climbers are likely to have a couple of carabiners to spare while in camp.

Like a chocolate river from the world of Willy Wonka, the Rio Horcones pumps silt, mud and mule dung down glacially formed valleys that descend from the summit of South America. The Vecto-Versa handled it well. [Photo] Tad MccreaLike a chocolate river from the world of Willy Wonka, the Rio Horcones pumps silt, mud and mule dung down glacially formed valleys that descend from the summit of South America. The Vecto-Versa handled it well. [Photo] Tad Mccrea

The bottom line: if you are on the market for a new lightweight, wallet-friendly water filter, I would recommend this system.

It is more compact, simple and efficient than traditional pump systems; more durable than a Sawyer Mini, and sits at a much more manageable price point when compared to gravity kits such as the MSR Trail Base. One of the only additions that I would really like to see out of the Vecto-Versa system is an option that allows larger bladders to be used, which would be nice for base camp setups, such as that included with the MSR AutoFlow XL Gravity Filter.

Chemical drops such as Aquamira or iodine tablets are obviously lighter and more compact, but the Vecto-Versa doesn't feature a chemical-ridden taste and a 15- to 45-minute waiting period before ingestion. UV light purification systems such as the SteriPEN will kill the tiny viruses (smallest of the waterborne disease-causing microorganisms) but can be unreliable in the field and require batteries. The Vecto-Versa, on the other hand, honors the code of simplicity.

Tad McCrea is an explorer, guide, photographer and longtime Alpinist contributor. He has done first ascents in Alaska, California, Patagonia and India.

Durable materials paired with intelligent design
Lightweight, tight package
Easy to clean in the field
Fast and efficient filter time
Both hanging and squeeze options

Larger bladders would be beneficial for expedition use
Does not remove viruses


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