What is a water purifier?
A water purifier removes undesirable chemicals, biological contaminants such as protozoa, bacteria and viruses, suspended solids, heavy metals and gases from water. But do not confuse the water purifiers with simpler water filters. Something that we learnt in our search is that a water purifier removes viruses while water filters cannot. The size of the technologies that lies within is way smaller in water purifiers, so that the viruses (far smaller than protozoa and bacteria) also cannot pass through it. This applies also for heavy metals, that some filters neither can let out.
With a water purifier not only you can drink water from almost everywhere, but also you incredibly reduce the use of plastic, as you do not need to buy bottled water to drink.
The systems we considered
There are many purification and many filtration systems. We are going to compare what we found trying to summarize all so you have the info you need.
In this comparison we are going to talk about different options that we checked while deciding for a purifier for our trip through south-east Asia, so we will focus our reviews on what is important for us while traveling, that is different than what is important in camping trips, for example. We have read so many reviews of different kinds of filters and purifiers, seen comparison videos, read specifications and all the necessary, spending so many hours until we decided. We hope we can save you all that time and you find this summary useful.
Our main goal was to get something that gives the safest/healthiest water, avoiding the bottled water and the waste of plastic that they bring. We were looking for something easy to carry and compact, not needing to mount few parts together every time we wanted to filter water. We wanted also something easy to use and versatile, as we did not know exactly what kind of trips we were going to do and what our water sources were going to be. In some countries we were going to rent at Airbnb, in others maybe camping, couchsurfing, hostels etc. So we needed a filter or a purifier that could keep up with all the possibilities.
In general, these systems have a first stage filtration, taking out of the water the different pathogens and microplastics with different filtering techniques. Some of them have a second stage, usually with an activated carbon filter, that absorbs metals and chlorine and improves the odor and flavour.
We will not go into all the details of every category of filters or purifiers, but give the overall and direct information summarizing our research and decisive factors for us. Then we will talk about the two best options from our point of view. The prices shown here apply to europe. If you just want to know our decision, here is the conclusion.
We would group the filters or purifiers in the following categories:
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UV light and pills
These systems are really compact and can work in any water recipient, or any with a big enough opening in the case of the UV lamp. You put the lamp or the pill inside and in a little time it is done (UV: around 1/2 min, depending on the model of UV light. Pills: between 30 and 60 min).
We discarded UV light systems and pills mainly because with these you take the water from your water source, put a pill or UV light bulb in it that kills microorganisms, but they do not take out metals nor particles.
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Pumps
With these you pump the water through the filters. You put one end of the tube on the water source, the other wherever you want the clean water and then pump. We see this best for rivers and large water sources. A good thing about this system is that you can filter much water at once and store it in different containers already clean.
We discarded these because they are not versatile enough, you still need a recipient for the clean water, the set up is relatively complicated in some models and they generally filter slow, depending again on the model.
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Straws
This is the simplest and easiest way of drinking safe water. You put the bottom side in the water source and drink from the other end. We liked these systems because of their durability and price. They are also compact and super easy to carry around. If you go for this kind, we recommend you LifeStraw or Sawyer.
However, some versions of these are not confortable for all water sources, as you have to go close to the water. With others you fill a bag of water and then use the straw from it, but none of the cases allow other uses that is not just drinking water, as you cannot filter much at once and you drink by sucking the water through it.
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Dirty/Clean water Bags
They consist of a bag for dirty water, some times a tube, and a straw-like filter. With these you only need to fill the dirty water bag, hang it and gravity makes it flow. If you go camping to a specific place, this is the choice from our point of view, because it allows you to have a big amount of clean water ready to use.
We discarded this system because it is not versatile enough and it requires time and somewhere to hang the bags. We wanted something easier to use.
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Bottles with filter cartridges
These are, in our opinion, the perfect ratio between compact and versatile. They typically include a straw-like filter through which you drink, and it is placed inside of the dirty water deposit, filtering the water as you drink, like the LifeStraw Go in the picture. Others work by pressure pushing the water throug a filter or purifier.
We decided for this kind of purifiers for our travel, as they potentially adapt better to the different situations we may have and the different water sources we might find. There are many of these in the market, but not all of them take out the parasites and/or viruses. See our top picks below.
The bottles we considered
So, decided about the category, we got to the question... Which model? There are many, but be careful if looking for one, as some brands have their version of water filter to go (not water purifier) for sport and other activities in areas without risk of contaminated waters. Those are not suitable for filtering just from anywhere, only tap water. So pay close attention to the specifications. That said, after much research we got 2 winners, the LifeStraw Go and the GRAYL.
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LifeStraw Go
LifeStraw is one of the leading brands in filtration kits. This specific model, the LifeStraw Go, weighs only around 220g and has a capacity of 650ml. It consists of a bottle for storing the dirty water and a straw filter to suck the water through it.
It uses one award winning, 2-stage filter cartridge (microbiological and carbon filters) that is in reality two independent filters.
Stage 1: A hollow fiber membrane removes
- 99.999999% of bacteria (E. coli)
- 99.999% of parasites (Giardia, Cryptosporidium, etc.)
- 99.999% of microplastics
Stage 2: A activated carbon capsule reduces
- Chlorine
- Bad odor and taste
- Organic chemical matter
The hollow fiber filter can filter up to 4000L. But the pores clog with the use, so whenever the lifetime is over water cannot go through and you can no longer filter. The carbon filter has a lifetime of 100L, but with frequent use, the brand recommendeds to change it every 3 months.
The LifeStraw Go is one of the most cost effective filter bottles you will come accross, costing around 40€ with one set of filters included. Then, you can buy another set for around 25€, and 2 carbon filters for between 10€ and 16€, depending on retailers. With this bottle you pay 0.05€ or 0.06€ per liter of water that you filter.
As disadvantages we point out that it does not remove viruses or heavy metals, and that it still is a straw, so you suctionate the water through it. It means, no large amounts of water at once and a decreased flow rate (12L per hour. 200ml per minute). Also that it does not cover your needs of safe waters for hygiene or to fill other reusable bottles in the case you need more water some days.
This is though a really affordable choice. To drink safe water in outdoor activities from time to time, where the risk of viruses is low is the best choice.
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GRAYL purifiers
As we continued researching about bottles with filters we did not see any that filtered all out, until we got to these. We have found the GRAYL purifiers to be beasts of purification, not only for all that they let out, but also for its flow rate. There are two models in the market now: GEOPRESS and ULTRALIGHT Compact. The first weighs 450g with a capacity of 710ml and the second 309g with a capacity of 473ml. They consist of a container where you put the dirty water and another container with the filter cartridge on the bottom which you push inside of the dirty water forcing the it through the cartridge. It is not as hard as it sounds, they have a flow rate of 5L per min (GEOPRESS) and 2L per min (ULTRALIGHT Compact).
It uses a single filter cartridge which, thanks to ion exchange and ultra-powdered activated carbon, removes:
- Waterborne pathogens including Rotavirus, Hepatitis A, Norovirus, Giardiasis, Cryptosporidium, E. Coli, Cholera, Salmonella, Dysentery and more
- 99.99% of viruses
- 99.9999% of bacteria
- 99.99% of protozoan cysts
- Particulates (i.e. silt, microplastics, etc.)
- Chemicals
- Pesticides
- Heavy metals
- Bad odor and taste
The GEOPRESS costs between 90€ and 100€, depending on retailer. The cartridge lasts around 350 filtering cycles, so 250L. Change it when a cycle takes around 25s, or 3 years after first use. The ULTRALIGHT Compact costs between 70€ and 75€, depending on retailer. The cartridge lasts around 300 cycles, so 150L. Change it when a cycle takes around 30s, or 3 years after first use. A cartridge for both GRAYL purifiers costs between 25€ and 30€, depending on retailer. That means around 0.11€ per liter.
The disadvantages we find in the GRAYL purifiers is the price and the cartridges lifetime. Also, because of the idea of these purifiers and their construction, taking the inner container out is a little hard. Other disadvantages that we saw specifically in the GRAYL Ultralight Compact is that the pressing area is the top of the internal deposit, so it has a risk of cross-contamination, it has less capacity and the filter can purify 150L, 100L less than the GEOPRESS.
What we loved about them is that they put together the purification of water (not just filtration) and the possibility of purifying larger amounts of water all together in the same system, in a not-so-bulky bottle. Their durability thanks to strong materials is also worth mentioning. We found the GRAYL bottles so innovative when we read about them. Even though they are pricey, for an everyday protection this is our choice.
Conclusion
We decided ourselves for a water purifier bottle and not any of the other systems reviewed because the bottle systems seem the most versatile systems for all kinds of traveling. We chose a GRAYL purifier because they are the most complete we have seen, letting out also viruses and sediment that other filtration systems let in the water.
Specifically we decided for a GRAYL GEOPRESS bottle, because it has the advantages of all the systems that we reviewed and covers all our needs, with the only drawback of needing to carry more filter cartridges with us for the long trip.
We preferred the GEOPRESS over the ULTRALIGHT Compact because of its bigger deposit and because its filter can purify up to 250L (100L more). It also includes a different lid that makes drinking from it really confortable and protects against cross-contamination, as you press on the lid.
With this bottle you have the possibility of purifying more water and storing it it in other bottles, in the case that you need more than the 710ml that GEOPRESS can hold. Not needing to suctionate the water with the straw like in other systems means, for example, being able to always take water for brushing your teeth or washing your face and hands with the same system that gives you water anywhere to drink. That was something decisive for us, and not usually taken into account for comparisons online.
We are so happy with our decision after one month using of the GeoPress in India, and we can only recommend it to everyone. This bottle really is the best purifier with the versatility we, as travelers, were looking for.