How to Purify Water 8 Ways and Survive |
Food & Water

How to Purify Water 8 Ways and Survive

Reading this article could mean the difference between surviving a global disaster or ending up as one of the millions of victims. Don’t be the one who forgot to check out this survival guide on how to purify water when the odds stack against you.

Did you know that a human being could survive without food for almost 3 weeks? 21 days without a single morsel, just like Mahatma Ghandi during his hunger strikes.

But without water? About 3 days. Yup, just 72 hours is all it would take for you to completely shrivel up and die if you don’t get access to water.

Text area which says "How to Purify Water 8 Ways and Survive," followed by a photo of a man purifying water from a lake

Don’t I already have water?

“But water is readily available isn’t it?” I hear you ask. Yes, in today’s modern world, access to clean drinking water is becoming much more common than a hundred years ago.

But where would you be if a global disaster occurred, one that strikes without notice? Within minutes, the electricity running the pumps shut down. The taps you’ve relied on for your entire life no longer work.

Granted, this is probably a far-fetched scenario, but the odds are that such an event could be possible. Maybe not in the near future, but in the years to come?

There are, of course, other situations more prone to happen, like running out of gas on a lonely highway or getting stranded on a deserted island.

Being stuck in such a situation could also feel like humanity decided to leave you out in the cold, or heat.

So, where’s the water at?

Believe it or not, water is everywhere. It’s all around you this very second, regardless of where you’re reading this article.

The trick is to have the knowledge to locate it before you really need it. Need proof? Go to your refrigerator and take out a soda can. Watch as small droplets of water begin to form on the surface of the can.

That right there is water, the water vapor that’s all around you turning back into a liquid.

But finding a cold soda can to produce water isn’t exactly a solution to survive humanity’s collapse. For that, we’re going to need to be more practical.

Luckily, there are amazing products to help us once we find the water. However, some won’t do much until we have the actual water in front of us.

What do I look for?

Like I mentioned before, water is everywhere, regardless of your location. Take a moment to check out your surroundings and look for any of the following.


Any animal in the wild will have one priority when it wakes. Drinking water is the number one chore for every living thing on the planet. For the animals, the best time is first thing in the morning.


Even insects need a belly full of water and if you see a swarm flying near you, then there’s bound to be a water source nearby.

Low-lying Areas and Valleys

Remind yourself that water flows downhill, then take a look at your surroundings. See any valleys? That’s where you should start.

Green Vegetation

If there is a distinct patch of green plant growth, chances are that water may be just below the surface. Try digging in a few spots until you strike pay dirt.

Muddy Areas

Despite the obvious, a dry patch of mud isn’t dried up. Water may be sitting just below the surface. If you dig a hole around a foot deep and a foot wide, water should fill it.


This option isn’t an error. Taking the time to stop and actually listen to your surroundings could prove fruitful. The sound of running water travels incredible distances.

Knowing these six options can mean the difference between living and dying in extreme circumstances.

There a few more options further down, but for now, I think they make my point. There really is water everywhere.

Finding water isn’t the problem. It’s what to do with it once you’ve found it.

Can I Just Drink It?

In a word, no. Finding unconventional water sources, although gratifying in itself, can be extremely dangerous if consumed without preparation.

Feces, blood, urine, toxic chemicals and various other forms of contaminants could be in the water. They need to be removed, to make the water safe to consume.

One method we could use is water purification. So, how to purify water?

Numerous products are readily available to purify water. From simple Water Purification Tablets costing just a few dollars, to products resembling a John Rambo super-weapon for desalinizing saltwater costing several thousand dollars.

The nasties that live in your water

Photo of a man holding his stomach in pain

Purifying water is imperative for you to survive when everything else goes to hell. The bacteria living in stagnant pools or alternative sources of water can invade your insides.

They multiply and leave you either severely sick or even dead. Here are just a few waterborne viruses you might encounter if you don’t treat your drinking water. In fact, this is why it is so important to learn how to purify water.

Virus #1: Traveler’s Diarrhea

Commonly known as Bali Belly, Delhi Belly, Hong Kong Dog or Tourist Trot. Contracted through consumption of fecally-contaminated food or water.

The symptoms associated with this condition include nausea, diarrhea, vomiting, abdominal cramping.

Virus #2: Salmonella

This is spread by ingesting human and animal feces, the bacteria living in the intestines of infected bodies.

Salmonella can contaminate water when dropped near sources such as springs, creeks, rivers or lakes.

Symptoms include vomiting, fever, diarrhea, and dehydration. If the virus enters the bloodstream, the result could be fatal.

Virus #3: Dysentery

This kills almost 700,000 people worldwide every year. It’s often found in water polluted with feces and can be passed to others via fecal-oral contact. Symptoms include bloody diarrhea, vomiting, fever, blood or pus in stools.

Virus #4: E. coli

It is found in the intestines of healthy cattle or infected humans and animals. It enters the water system in various ways including storm run-off or sewage overflow.

Symptoms include bloody diarrhea, vomiting, fever and in more extreme cases, kidney failure.

Virus #5: Typhoid Fever

This is a disease that can continue to live in previous carriers who’ve recovered from the disease. It can be caught from someone by eating or drinking beverages handled by an infected person.

A common cause of spreading is failure to wash hands after using a toilet. Symptoms include a sustained high fever, stomach pains, headache, weakness, loss of appetite and constipation.

Virus #6: Cholera

It is a disease that can lead to death within a few hours. The bacteria is passed on through unsanitary conditions, spreading into water supplies and the food washed in it. Symptoms include profuse diarrhea, dehydration, fever and death.

Virus #7: Hepatitis A

This is a liver disease that is caused by the Hepatitis A Virus, or HAV. It’s spread in much the same way, through fecal matter making its way into the water supply.

Symptoms include Jaundice, dark urine, fatigue, vomiting, fever and nausea.

Virus #8: Campylobacter

This is the most common bacteria to cause gastroenteritis around the world. The onset of symptoms take anywhere from one to ten days and include fever, headache, nausea, vomiting and abdominal pain.

There are plenty of good reasons on this list why it’s ill-advised to drink untreated water. The chances of being infected by a single bacterium, dropped by a lone animal as it meandered past your water source are too great to ignore.

And this list doesn’t include the parasites, roundworm or river flukes; pesticides; heavy metals or synthetic organics; strange colors from microscopic algae; odor from bacteria.

If you are caught in a world where water has become a rare commodity, then chances are medical help is also unavailable.

Imagine being struck down by any one of these. How long could you really last without a medical practitioner to help make you better?

How to Purify Water: What is the Difference Between Filters and Purifiers?

Not all solutions are as effective as needed and when answering this question, you should ask another.

Why do I need it? Something to consider when answering this question is the circumstances that you find yourself in.

Has your vehicle broken down while driving cross country to a new life?

Did your ship sink and you swam safely to some nearby island?

Did the world really end and you ran for the hills as fast as you could?

What it all comes down to is planning and mobility.

While water filters and water purifiers may sound like the same thing, they are in fact different. Water purifiers have one extra element which makes them a lot more appealing than a filter, an element that could save your life.

Water filters remove protozoan cysts and bacteria, biological pathogens which are of concern when traveling in Canada and North America.

These types of filters are popular with many homes, but that’s another topic entirely. Our homes are gone, remember?

If you’re traveling in other parts of the world, or humanity has crumbled and we find our water sources contaminated, water filters will struggle where purifiers will shine.

Whilst the filter may work against larger organisms and bacteria, they are of little use against waterborne viruses too small to be trapped.

Water purifiers remove everything a filter can. But it uses other ways to combat the viruses living in the water that are too small for filter elements to catch.

It’s those viruses that have the potential to kill you in extreme cases, so options to remove them should be considered.

Adding chemicals, such as iodine that kills viruses, or ways to use ultraviolet light, make Purifiers far more worthy when things go wrong.

Is there more to how to purify water?

Besides filters and purifiers, there are other products worth considering. The water itself may be mucked up because of rainstorms stirring up mud, leaves, silt or sediment.

Although not harmful to you, they can affect the effectiveness of your purifier, reducing the overall lifespan of your product.

Activated Carbon is a great additive to any filter or purifier as it can remove the bad taste associated with leaf tannins.

It also works to remove harmful pesticides and other industrial chemicals that might be present in the water.

Pre-filters, already present in some products while needing to be purchased for others, act as a kind of big brother to your purifier.

They remove the big things that may clog the system so that the cleaning process runs smoother.

Pre-filters help to-

  • Maintain the flow rate
  • Increase the effectiveness of chemical treatments
  • A must-have before using a UV Purifier on non-clear water
  • Extends element life
  • Lessens cleaning chores

Most pump-style filters already come with a pre-filter and it’s worth checking yours. If it doesn’t have one, simply purchase a pre-filter extra.

How to Purify Water 8 Different Ways

Now for the pointy end, the part you’ve been patiently waiting for; the different types of filters and purifiers available.

The following list highlights the various ways and methods available to treat any water source available to you, so you can choose how to purify water for you and your family.

Although some are more conventional, others can be remarkably effective with relative ease.

  • Pump Filters and Purifiers
  • Gravity Filters and Purifiers
  • Ultraviolet Purifiers
  • Bottle Filters and Purifiers
  • Squeeze Filters
  • Straw-Style Filters
  • Chemicals
  • Boiling

In fact, each item on the above list can be used in almost any situation, but it’s important to remember that you still need to consider your surroundings to determine which contaminants may be present.

Which Do I Choose?

Reading through the list may prove to be somewhat confusing, so let’s check out the pros and cons of each so you can choose how to purify water for your situation.

Method #1: Pump Filters and Purifiers

As simple as dropping one end of the hose into your water source and the other into your water bottle. The flow rates and pumping mechanisms vary between models, so choose one for your needs.

Photo of a water pump type purifier Pros-

  • Pump only what you need
  • Use on shallow sources
  • Replaceable element or cartridge


  • Pumping is a chore
  • Element needs field cleaning
  • Larger and heavier

=> Check out on Amazon

Method #2: Gravity Filters and Purifiers

These filters and purifiers are as simple as finding a suitable source of water, filling the reservoir up and then hanging the whole thing somewhere and waiting for your drink.

However, whilst size and number of reservoirs can vary from one model to the next, most of these have an in-line filter. Check to see which model is suitable for your needs.

Photo of a Gravity filter and purifierPros-

  • All the work is done by gravity
  • Larger quantities can be processed if in a larger group
  • Comes with replaceable elements or cartridges


  • Needs a place to hang to work
  • Much slower than pumping
  • Shallow water sources may be difficult to use
  • Needs field cleaning

=> Check out on Amazon

Method #3: Ultraviolet (UV) Light Purifiers

The simple pen-style of this device is what makes them very attractive. Hold it in your water supply, push a button and stir until the UV light turns off. Within a minute you’ll have treated water ready to drink.

Photo of an ultra-violet light water purifier


  • Simple treatment
  • Quicker than other methods
  • No element to clean


  • Needs batteries to operate
  • Needs pre-filter if water is cloudy or silty
  • More treatments needed for larger quantities

=> Check out on Amazon

Method #4: Bottle Filters and Purifiers

With built-in filtration or purification elements, this option is as easy as filling a bottle and drinking away. While some use the actual drinking suction, others use a system similar to a coffee press. UV is also an option.

Photo of a bottle filter


  • More affordable than pump or gravity
  • Simple to operate
  • Fast drinking water available
  • Replaceable cartridge or element


  • Bottle limits water amount
  • Field cleaning needed

=> Check out on Amazon

Method #5: Squeeze Filters

Although very similar to bottles, these are used by filling a much smaller reservoir and squeezing it through a filter.

Photo of a squeeze type water purifier


  • Simple treatment
  • Water is quickly turned drinkable
  • Some models can double as a straw-style filter or gravity filter
  • Much lighter and smaller than pump or gravity filters
  • More affordable than some other options


  • Limited size due to reservoir
  • Needs field cleaning

=> Check out on Amazon

Method #6: Straw-style Filters

One of the few on-demand products that works like a regular straw. Simply submerge one end into your water source and sip on the other. The filter is in-built.

Photo of a straw-style water purifier


  • Very simple to operate
  • Much lighter to carry
  • Less bulky than other options
  • More affordable
  • Instantly drinkable


  • Only used at the water source
  • Some models have no replaceable element
  • Field cleaning is needed
  • A single person treatment option

=> Check out on Amazon

Method #7: Chemicals

These are chlorine or iodine-based and are effective treatments against viruses, bacteria and protozoa.

They come in a variety of options including tablet/pill form, drops or a gadget that mixes the base ingredients together. It’s as simple as dropping your product into the water and waiting.

Photo of a commercially sold bottled chemical used in purifying water.Pros-

  • Simple to use
  • One of the most affordable methods available
  • Easy to carry
  • Makes for a perfect back-up


  • The waiting time can stretch to 4 hours, longer for colder water
  • Pregnant women and people with thyroid conditions are a concern for iodine
  • Iodine is ineffective against Cryptosporidium
  • Can taste chemically, particularly iodine products. Can use taste-neutralizers.

=> Check out on Amazon

Method #8: Boiling

Utilize this method with items you already have. A stove, fuel and a saucepan or pot make an effective treatment system against all biological pathogens, provided the water is boiled for a minimum 1 minute, or 3 minutes if above 6,500 feet.

Photo of a small saucepan used in boiling water in the wildPros-

  • Only dependent on fuel
  • Perfect back-up method when other options fail
  • Murky water doesn’t interfere with boiling effectiveness


  • Water requires time to boil
  • Cooling time for drinkable water
  • Extra fuel needed if primary method

While some of the above methods can be used with very little planning or effort, all of them must be considered when choosing a suitable option. There are many factors to consider prior to handing over your hard-earned money, so choose wisely.

Any more things I should know on how to purify water?

To ensure the effectiveness of any method you choose, it’s a timely reminder to take some precautions and avoid some key mistakes. While some may seem obvious, others may be simple things that can be overlooked when pressured for time.


You should take into consideration the temperature of your surroundings when using the above methods, particularly when it’s below freezing point. Some filters and elements can be susceptible to the cold, freezing and cracking in the harsh conditions.

One way to overcome this is to store them with you in your sleeping bag. Batteries tend to fade quicker in the cold so bring spares. Chemicals’ effectiveness may be reduced in colder weather. Be sure to read all instructions thoroughly before purchasing them.


You must make sure to locate your own camp, particularly your toilet and washing facilities, a minimum of 200 feet from your water source, otherwise you may be introducing the very pollutants you’re trying to remove in the first place.


When possible, seek out the cleanest source of water possible. Remind yourself that any sediment is going to impair the cleaning process. If murky water is your only option, use a pre-filter if you can, or wait for sediment to settle to the bottom of your container beforehand.


Keep your dirty containers away from your clean ones and always keep your own hands clean with sanitizer.


No matter what product you purchase, always read the instructions carefully, noting any specific points that may reduce the effectiveness of the product. The warranty on these products, as well as any liability, could be voided if directions aren’t followed as specified by the manufacturer.

How to Purify Water: The Final Word

The benefit in today’s world is that there is an abundance of choice and the relative ease of how to obtain the things we need. However, while the world may collapse one day, I hope it doesn’t for a long time to come.

But now that we know so much more about water purification, why not plan that next camping trip, equipped with the knowledge you learnt here. Who knows? You might just find yourself pumping crystal-clear water from a mountain spring overlooking a vast wilderness, thinking “I could survive here.”

And maybe one of these days you will, so it’s important that you learn how to purify water under difficult circumstances.

You may also want to read this article on water conservation: 6 Tips to Conserve Water for Survival