Best Survival Water Purifiers - A Comprehensive Buying Guide
Imagine you come to your countryside cottage, but instead of clean fresh water in the well you see tainted mud. Having enough clean water to drink is essential, so that is where the need for a water purifier arises. In this guide we will tell you about various kinds of water purifiers (their portable versions), ways to make one yourself and what alternatives there are.
Drinking tainted water is not an option in any case, so in any situation when you do not have access to clean fresh water, it is a signal for you to obtain a water purifier of any kind.
Among those who definitely need water purifiers are the following:
Those having dirty water in the tap. Sometimes water purifiers are a great need not only of those who are far away from cities and towns, but also of big city citizens. Water found in our taps often leaves much to be desired, so purifying is a must;
Avid travelers. This kind of people is always present when we consider some gadget or tool that is portable. Travellers are always on the go, that is why they often find themselves in places where the quality of water is unclear (sorry for the oxymoron!);
People who do not have their own water at all. It is not necessary to wander far into the forest to be deprived of fresh water. Owners of countryside houses that have their own wells are often not satisfied with what they see in the bucket. Here is where water purifiers become essential;
Travelers who got lost. No panic. If you are lost somewhere, it is vitally essential to know some tricks that may help you survive. The ability to turn water from a river into drinkable water is one of those.
2. Why do I need to treat water?
Some things are evident, and you might exclaim, ‘Why on Earth should I read about the dangers of bad water, I’m not stupid!’. The matter is that you might not know HOW dangerous it is. These issues are related mostly to water found in the wilderness. The chance of experiencing something like this from tap water is low, so consider purifying water every time you fill bottle from a river, because:
It may be tainted. Water may seem fresh and clear, but you cannot see pathogens hiding in it. Any source of water, whatever reliable look it has, may cause severe diseases, such as fever, diarrhea, vomiting or worse. It all depends on what such ‘calm waters’ have in store for you;
It may hide viruses. This danger is closely connected to the previous one. Among viruses often found in wilderness water are hepatitis A, rotavirus and others;
It may hide parasites. Water is a good home for parasites, many of which will be happy to find a human body as a master. But we would expect them to serve the master in the conventional way…
Now that we have persuaded you (a least we hope so!) that water purification in necessary, consider getting a portable water purifier that fits your needs.
3. Water purifiers VS water filters.
Despite their names looking quite similar, water purifiers and water filters are different things. The difference is in the usage of a chemical treatment featured in water purifiers. Water filters use a technology of microfiltration that deprives water of bacteria and protozoa, whereas water purifiers combine with additional chemical treatments that kill viruses.
In most cases water filters are the best option since they provide additional water treatment and seem to be more reliable. It requires some investigation, though, because not all purifiers are as effective as filters.
To call a device ‘a purifier’ it should meet the U.S. Environmental Protection Agency (EPA) Guide Standard and Protocol for Testing Microbiological Water Purifiers, that is to say it should deprive water of 99.9999% of bacteria, 99.99% or viruses and 99.9% of protozoa.
4. Ways to purify water.
Since this issue is of utmost importance, there have been developed many ways to make water drinkable.
We would also like to note that since we consider only portable water purifiers, we are not going to discuss filters that are attached to taps and so on. Here is a comparison of different types of portable water purifiers.
So the first classification of means of water treatment is the following:
Mechanical filters. This type of devices is a reliable one since it has been in use for a long time and proved to be efficient. All mechanical filters fall into two large groups: gravity and pump.
Pump filters. They have such a name due to its method of purifying water. Such a filter does not, actually, purify water - it rather filters it. The device consists of two reservoirs one of which contains dirty water subject to cleaning and the other one being a container for drinkable water that is the result of pumping water through a special filter. That is it - as easy as that. Such filters have a lot of advantages over other types of water purification means in terms of:
Speed.Pump filters are capable of filtering 1-2 liters (33-68 oz) per minute, that is a good result in comparison with other devices;
Dimensions. The size of such filters vary from 15 to 50 cm (6-20 inches) in length and 5-10 cm (2-4 inches) in width. They are lightweight - 200-400 g (7-14 oz);
Purifying/filtering efficiency. Most filters are ceramic cartridges or other filtering media types that have pores that are smaller than the size of bacteria. Although, as we have already mentioned it, filter only filter water, that is to say they do not eliminate viruses from water;
Convenience. All you have to do is to put some (though little) effort to pump water. It is not that hard and does not mean you will have to struggle working all days long pumping water like a Roman slave;
Cleanability. If water proves to be muddy, it may be necessary to clean your filter. Most filters are easily disassembled and can be cleaned in the field. Note that unprotected glassfiber cartridges should be removed and replaced since they cannot be cleaned. Here is a tip on how to realize it is time to clean your filter: when it gets difficult to pump, it means that there is some obstruction (generally, mud and parts of filtered thing) that needs to be removed, i.e. cleaned;
Durability. Most filters are told to have the capability of filtering up to 3800 liters (1000 gallons) of water. The cleaner the water you filter is, the longer your filter will serve;
Taste. Water filtered with such devices generally has natural taste. If filter media features carbon, it can eliminate smells remaining from plants that used to grow in this water.
Gravity filters. Another member of the mechanical family is a gravity filter. It is a version of a pump filter that is even more convenient in use. The principle is the same, the implementation is different: gravity filters have two reservoirs just like pump ones, but they do not require any manual work. You see, they don’t call it ‘gravity filter’ for nothing. All you have to do is to hang one bag above the other. All the rest will be done by… gravity. Water will flow from the upper bag to the lower one through a filter media and get clean. It shares the advantages of a pump filter and has some additional ones:
Speed. Normally it takes some time for water to flow through the filter, so a speed of 1 liter per minute is average. The bigger the filter diameter, the faster it filters water. Most people prefer to hang the upper bag and attach it to a tree or something like that instead of holding it;
Dimensions. Since the reservoirs are bags, when there is nothing in them, they are flat and do not take much space. With hoses and filter ready for usage, the dimensions are the same as those of pump filters’. Average weight is 300-500 g (10-17 oz);
Purifying/filtering efficiency. The same as in the case of pump filters.
Convenience. The only drawback is that it may be difficult to find a place to hang the bag. It may also be inconvenient to fill the bag with water if it is hard to reach to. If you manage to get water in and are ready to hold the bag, then these are not problems;
Cleanability.The same as with pump filters. Gravity filters are easily disassembled and cleaned if needed;
Durability.Gravity filters can provide you with 700-1500 liters (185-400 gallons) of drinkable water. Like pump filters, they will serve longer if you use as clean and mud-free water as possible. Remember to dry filters after use in autumn and winter, otherwise they may freeze and get broken;
Taste.The same as with pump filters. In general, taste is altered when chemical agents are used, which is not the case.
Chemical purification. Though tested and cheap, this method should be used with great care. There are drawbacks that do not allow us to call it a good option. There are two agents used in most cases: chlorine dioxide and iodine.
Speed. It takes some time for chemical agents to ‘act’, so the speed is quite low. Also, the speed depends on water characteristics, such as temperature and murkiness. Cold water needs more time to get drinkable. Depending on the purifying agent, time varies from 15 minutes to 4 hours;
Dimensions. Since chemical agents are tablets or crystals, they can easily be transported in any small bottle or container. It is a leader of all purifying methods in terms of carrying convenience;
Purifying efficiency.The first thing that should be noted is that chemicals do not kill Cryptosporidium - a parasite that is sometimes found in ponds and other waters and that has such a hard shell that it is not affected by common chemicals. Second, other bacteria are destroyed quite effectively. Third, and the most important, chemicals DO NOT remove any garbage, particles, plants, mud, sand and other things one does not want to see in a glass. So use chemicals as a means of purifying water only if there is no other way to do it or if you have additional equipment to filter water from litter;
Convenience.Extremely easy to use. Just drop the chemicals (tables, crystals, etc.) into the water and wait for it to ‘get ready’. Of course, you can disinfect the whole pond, but what to do with SO much water?.. More than that, you will need piles of chemical agents, so we recommend filling only some container. Gather enough water and add chemicals. And voila!
Durability. The only thing we should mention here is to care for two aspects: the date of expiry and the amount of supplies. Thus, you should check whether your agents still maintain their effect and whether you have enough chemicals with you;
Taste. It is definitely the worst thing about chemicals (along with the disability to filter particles). Iodine changes taste more than other agents. There are tablets that can be used to neutralize it, but it does not eliminate it completely. Chlorine dioxide also alters taste. Such water reminds of urban-chlorine taste. Well, since many of us are used to such water, this option seems to be better than iodine.
UV purification. UV technology of water cleaning is quite new, and though it has a lot of potential, it still leaves much to be desired. It has some advantages, but there are issues that make it less effective than filters, for instance: like chemicals, they do not remove any unwanted matter from water; they also need to be handled with care and great attention to instruction, otherwise ultraviolet water purifier may not destroy all of the pathogens’ DNA.
Speed. It takes only 1.5 minutes to clean 1 liter of water. Just make sure you have exposed water to UV for the exact amount of time (no less than the needed time stated in the manual);
Dimensions. Such devices are highly portable. The average size is 15-20 cm x 2 cm (6-8 inches x 0.8 inches). Average weight is 250-450 g (8.8-15.8 oz);
Purifying efficiency. UV light is capable of destroying bacteria, protozoa and viruses, but does not eliminate unwanted matter from water. It means you will have to use some other filtering device if the water you are purifying contains particles and other stuff;
Convenience.Since dimensions of UV water purifiers are small, it is easily transportable. It is convenient in use, but it is recommended to purify only close-to-clean water that hardly has any matter in it. If you have to handle with muddy water, you’d better expose it to UV light twice more to ensure it has affected all the water ‘inhabitants’. Stir the water so that particles would not prevent the purifier to affect ALL the water;
Cleanability.You do not need to clean UV purifiers at all;
Durability.You need to have enough batteries with you so that you would not be left without drinking water. Alkaline batteries can keep it working long enough to purify 15 liters 9507 oz) or water. If that is not enough, consider using NiHM ones which will grant you 100 liters (3380 oz). Take care not to break fragile elements (glass parts) of the device;
Taste.One of the best features of UV water purifiers is that they do not alter the water taste. We mean, at all.
Boiling. Good old boiling is right what you need is if you are caught unawares and have nothing else to apply to water. Normally water boils at 100 oC. Although, it depends on the altitude. If you have to handle water purification in the mountains, the following table may come in handy:
Boiling temperature, oC/oF
Boiling temperature, oC/oF
100 / 212
90,0 / 194
98,3 / 208,9
88,3 / 190,9
96,7 / 206
86,7 / 188
95,0 / 203
85,0 / 185
93,3 / 199,9
83,3 / 181,9
91,7 / 197
80,0 / 176
The best way to disinfect water is to boil it for 8-10 minutes. If water is taken from an unreliable or tainted source (which should be done only if there are no other ways to get water), boil it for 30 minutes.
Water kept at 70 oC kills all protozoa within 30 minutes. Temperature of 85 oC or above kills them way faster - within a couple of minutes.
40 minutes are enough to sterilize medical syringes, provided the atmosphere pressure is normal.
Speed. Takes a lot of time. You have to set the fire, place the kettle (or whatever you have), wait for water to get to the needed temperature, wait for some minutes for it to boil (to kill the unwanted bacteria, etc.) and then wait for the water to cool;
Dimensions. What are we talking about? Take whatever suitable bucket or kettle you have;
Purifying efficiency. Boiling kills bacteria, protozoa and viruses, but does not remove matter. Some unwanted stuff will gravitate down, though;
Convenience.Just find a clean vessel to boil - and here you go. If the water you are going to boil contains unwanted matter, you will have to consider additional filtering;
Taste. Boiling affects water taste since there are some salts and other components that gravitate down or evaporate.
5. Where to buy water purifiers.
It depends of what means of purifying you have chosen. If you aim at buying a UV water purifier or a filter, go for Amazon.com or stores that specialize in such devices. If you have decided to use chemicals, visit a drugstore and buy some iodine/other chemicals to your liking. Don’t forget to check the date of expiry. Normally such chemicals can be used within 1-3 years.
6. How to choose a portable water purifier.
Since the most important criterion of choosing a water purifier is purifying efficiency, the priority is given to filters and UV purifiers. Here are a few tips:
Choose pump/gravity filters if you need quite a lot of water and you are sure there are no viruses common in the local waters;
Choose UV purifiers if you do not need much water and you are sure there are no particles or unwanted matter in the water;
Choose chemicals if there are no other options available or you do not expect to be striving to find water. Take some chemicals with you if you go hiking - only God knows what may happen. Chemicals are lightweight and easy to carry.
Boil water. Boiling won’t hurt, as it helps ensure water safety.
Salt water can be turned into drinkable only by means of condensation (either by evaporation of collection using solar heat), so do not expect common portable filters and purifiers to make ocean water drinkable.
So the general pattern when choosing a portable water purifier is the following:
Consider how much water you need;
Consider how often you are going to use it;
Consider whether you are going to clean it in the field;
Consider what dangers are common in your local waters;
Consider what device you can afford (price can also matter);
Consider buying chemicals, just in case someone needs them.
7. Popular models of water purifiers.
Since there is a wide range of appliances for water purification, we will consider popular models of various types. All these models have wonderful ratings and are the best portable water purifiers.
If you get stranded somewhere in the wilderness, the only way out to find water is to make a DIY water filter. Prepare in advance and follow the steps needed to do it:
What you will need:
Plastic bottle with a cap;
Vessel for water.
Step 1. Cut the bottom of the plastic bottle.
Step 2. Make a hole in the cap using a nail or something narrow and sharp.
Step 3. Place the coffee filter on the bottle mouth and place a cap over it.
Step 4. Place the bottle upside down in a glass or vessel so that it would be convenient to fill it with filters.
Step 5. Fill the bottle (1/3 full) with activated charcoal. Break it into small powder if your charcoal comes in big pieces.
Step 6. Fill one more third with sand.
Step 7. Fill the bottle with gravel up to the top.
Step 8. Place the bottle into the vessel in which you are going to gather water.
Step 9. Pour water and wait for it to filter. Then boil it and pour into a clean vessel.
9. Useful videos.
Here are a few videos that you may find useful when learning how to make DIY water purifiers:
Water is essential for a human body. If you find yourself deprived of access to a source of fresh and clean water, you have to get a water purifier. There are many options available on the market. If you do not have an opportunity to buy one, it can be made on your own.
In most cases gravity filters prove to be the most efficient and convenient to use. For better protection, buy a UV water purifier to kill all the viruses that may pose a threat.
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