A portable water filter is a self-contained unit that may be used by recreational enthusiasts, military personnel, survivalists, and others who must obtain drinking water from untreated sources (e.g., rivers, lakes, groundwater etc.).
Table Of Contents
- Field Conditions
- Long Term Review
Walking along a trekking trail you come across a pristine mountain stream. “This is a perfect place for a breather”. You drink your fill from the stream, refill your water bottles and trudge along the way. A kilometre upstream there is an idyllic hamlet. You notice that the entire hamlet is using the stream for cleaning up after completing “their business”. The shocking realisation slowly dawns on you. This is the same pristine stream you have been drinking from. ~ Bhaderwah J&K (2015).
“Keep to the trail on your left” keeps ringing in your head as you make your way through a dense forest. This was what that helpful villager told you a day before yesterday. Since then the trail has almost disappeared and the forest has got a lot dense. Yet you resolutely move on. After bushwhacking for a few hours, the realisation sets in and you admit to yourself that you are hopelessly lost. “Keep calm” you tell yourself, as you recall the rule of threes: You can live 3 minutes without air, 3-hours without shelter, 3-days without water and 3-weeks without food. However, the only water source around is a dirty pond with murky, brackish water ~ A tale of 3 rescued trekkers, Barot H.P. (2015).
These are not hypothetical situations but real-life situations that I’ve had to deal with on my treks. On a trek through an uncharted realm or in a rescue and survival situation, the ability to distil drinking water from a non-potable water source may mean the difference between life and death. In either predicament, a portable water filter comes in extremely handy.
So what is a Lifestraw
Lifestraw is a hollow-membrane personal water filter built into a straw. It was designed and developed by the Swiss-based Vestergaard Frandsen for people living in developing nations and for distribution in a humanitarian crisis. Since then it has won several awards including the 2008 Saatchi & Saatchi Award for World Changing Ideas , the ‘INDEX: 2005’ International Design Award and “Best Invention of 2005” by Time Magazine.
Lifestraw is simple to use. Place the straw into the water, and drink. Sucking the water up through the straw forces it through the filter, which removes 99.9999% (Log 6) of bacteria, and 99.9% (Log 3) of protozoa, down to 0.2 microns. A built-in filter that lasts a 1000 litres of water, is a pretty good deal.
Bacteria removed include
- Escherichia coli (causes gastroenteritis, urinary tract infections).
- Campylobacter ( causes diarrhoea or dysentery).
- Vibrio cholerae ( causes diarrhoea or cholera gravis).
- Pseudomonas aeruginosa ( causes pneumonia, skin and soft tissue infections).
- Shigella ( causes diarrhoea and reactive arthritis).
- Salmonella ( causes typhoid fever, paratyphoid fever and food poisoning).
Protozoa removed include
- Giardia lamblia ( causes giardiasis).
- Cryptosporidium Parvum ( causes diarrhoea and abdominal pain).
- Entamoeba histolytica ( causes amoebic dysentery or amoebic liver abscess).
- Size: 9″ (23 cm) long x 1″ (2.5 cm) wide.
- Weight: 56 grams.
- Materials: Impact resistant plastic and patented filter system.
- Life Expectancy: Filters up to 1000 litres of water.
- Shelf Life: Unlimited – if kept at moderate temperature and does not freeze.
- What’s Included?: Comes with a neck/wrist lanyard, and a cap for the mouthpiece nipple, and end piece (filter end).
- Price: Rs 1100 to Rs 1200.
- Filters up to 1,000 litres of water.
- Removes 99.9999% of waterborne bacteria (>LOG 6 reduction).
- Removes 99.9% of waterborne protozoan parasites (>LOG 3 reduction).
- Reduces turbidity, filtering down to 0.2 microns.
- Lightweight: weighs less than 60 grams.
- Does not use iodine.
- Contains no chemicals (and is BPA-free), uses no batteries, has no moving parts.
- High flow rate; no after taste (because no iodine or chlorine are used).
- Easy to clean. Can be stored and used periodically. Just keep uncapped so it can dry thoroughly.
- Very durable, made of impact-resistant plastic.
- No shelf life. LifeStraw can be stored indefinitely.
- Used worldwide in harsh conditions since 2005.
- Doesn’t remove microscopic minerals.
- Does not remove heavy metals or chemicals.
- Doesn’t filter viruses less than 0.2 microns (Most viruses are smaller than 0.2 microns).
- Does not desalinate water (cannot be used to drink sea water).
The Lifestraw has been extensively tested in the Indian Himalayas for over eighteen months. The water sources ranged from glacier-fed mountain streams and dirty rainwater ponds. I have never had a waterborne infection in any of my trekking trips.
Long Term Review
At one kilo for every litre, water is the heaviest item in a backpack. Water can weigh you down if you carry too much. I often see trekkers carry three to four litres of water even when they are surrounded by water sources in the mountains. However, to make use of these natural water sources, a portable water filter is required.
Lifestraw achieves the same thing as most other portable water filters but at a fraction of their weight (56 grams). Given its lightweight and small size it a no-brainer to carry around in your backpack. Even if a Lifestraw saves you from carrying an extra litre of water, the weight savings (1000 – 56 = 964 grams) are substantial.
At 5 litres of water a day a Lifestraw will last 200 days. For a casual hiker, this translates to over 3 years of product life even if you trek 60 days in a year.
Ease Of Use
With a Lifestraw, there is no waiting time between reaching a water source and rehydrating. You simply dip the straw in a water source and start drinking. Compare this ease and simplicity with a pump filter where you have to a) collect water b) pump it through the filter c) store clean water and d) drink it.
Since the hollow-fibre filter in a Lifestraw has no moving parts, there is nothing that may break or stop working. Moreover, it does not require batteries or ancillary parts and the filter body is made of hard plastic. I have dropped it many times and it still works.
However as with all things a Lifestraw is not perfect either. Here’s a list of practical problems that I faced trekking with the Lifestraw
Lack Of Storage
Lifestraw does not allow you to fill a water container with clean water. It is a drink it or lose it solution. Since storing water is not an option, the Lifestraw is impossible to use in a scenario where you might not come across another water source in a day or so.
Another issue that I often faced was that the filter does not fit a narrow mouth bottle. Therefore I had to fill my cooking pot with water before I could drink it via a Lifestraw. It is not a big deal if you carry wide-mouthed bottles, but it is still something to be aware of.
It takes a few good draws on the straw to get it going when the straw is dry. This is can be disconcerting for a new user. However, the flow rate is quite good once the filter is wet.
A Sawyer Squeeze uses a better filter as compared with a Lifestraw. The Sawyer Mini has a 0.1-micron filter that removes 7-log (99.99999%) of all bacteria and 6-log of all protozoa (99.9999%) and it has a life span of 4,00,000 litres. In the US, Lifestraw and Sawyer Mini retail for a similar price but in India it costs just over Rs 3200.
“Fast, good and cheap; pick any two” is a choice I am usually faced with when buying trekking gear. Seldom do I come across a piece of gear that checks all these three boxes. Nevertheless, Lifestraw is one such piece of gear. I heartily recommend the Lifestraw for hiking and trekking. In winters when you have to melt snow to get potable water, the Lifestraw is not usable. But for every other trekking scenario especially in the Indian Himalayas, this is a must-have in your backpack.