How To Purify Water – 8 Essential Techniques That You Need To Know

When you hear the words “sustainable living in a small space” it might conjure up things like small, efficient gardening or raising small groups of animals.

Perhaps it brings to mind DIY agricultural and home-oriented projects, all taking place in a cramped, yet perfectly utilized space in a city or suburb.

But there is one important, easily-overlooked element that is a vital part of keeping your urban homestead humming along…


Whether you’re watering the plants in the garden, the chickens in the coop, or yourself after a superbly executed DIY adventure, you’re going to need good, plain, unadulterated water.

And as is too often the case, the water flowing through those pipesis just not always up to the task

Besides, being truly “sustainable” includes having a source of good drinking water separate from that city tap water or well driven by an electric well-pump.

That’s where knowing how topurify water comes into play.

Why You Should Purify Your Water

“Why are you telling me this? I get city water! It’s clear and clean and good to go.”

Yes, it might look that way on the surface (or through the glass), but really, there are some important reasons why water sterilization is touted by so many people around the world.

You see, filtered water can still be contaminated with all sorts of junk that floats around in there, just waiting to get into your system.

This article from Princeton starts out with a quick and helpful breakdown of the difference between biological contamination (bacteria, viruses, etc.), and toxic contamination (chemicals).

Both can be serious concerns depending on where you live.

The important similarity between the two is that you can’t see either of them. In order to be sure you’re getting clean and healthy water, then, it’s good to do a little bit of research into water purification and the benefits of clean drinking water (or have us at do it for you)!

Before we dive into the different techniques, let’s take a closer look at some of the scenarios in which purifying water is important.

Note: For extra info on sustainable techniques using water in general, check out these articles on aquaponics and aquaponic systems in small spaces!

Reasons to Purify Water Outdoors

what's in your h2o graphic

The classic image of someone needing to filter water is not a tourist at the beach or a parent feeding their kids – it’s someone figuring out how to purify water for drinking survival in a desert or the wilderness.

Now, let’s be real, very few of us have actually been in a “survival” scenario.

But if you’ve done something even as simple as camping, the thought of knowing how to purify water in the wild has probably crossed your mind.

When you’re in the wild, water can have a host of different issues. Bacteria like Giardia, E. Coli, Hepatitis A, and even scarier-sounding things like Cryptosporidiosis (an infection caused by a parasite) can be in the water.

In addition to bacteria, there can be chemical runoff from farms; sewage, garbage, and other pollution as well.

All of that said, whether you’re camping or surviving a zombie apocalypse, knowing different water purification techniques when you’re in the wild can really come in handy.

How to Filter Water Can Be Useful at Home, Too…

public health crisis graphic

Another area where this kind of knowledge can come in handy, is knowing how to purify water at home.

From sterilizing your own collected rainwater, to something as simple as learning how to purify your tap water, getting your hands on genuinely clean water is important no matter where you are in the world.

And we’re not just talking about backwoods areas or third world countries, either.

Many major cities all over the globe have water containing parasites and chemicals that can cause all sorts of issues.

This is even true for seemingly “safe” areas like the United States. It’s important not to make any assumptions about the cleanliness of your water.

Do some research on your local water quality as well as common water issues to look for in your specific area.

You can Google your region for clean water issues, or try calling an organization (like the CDC in the U.S.) to see if there is anything obvious to watch out for.

While you can always go out and purchase one of the best drinking water purifiers for day-to-day use, in this article we want to provide you with more than just the commercial options (although we’ll cover some of those too!).

We’ll Show You How Long To Boil Water to Purify It… and How to Clean Water Using 7 Other Methods

As mentioned above, there are many ways to purify drinking water (especially in a crisis), besides rushing out and dropping hundreds or even thousands of dollars on a fancy gadget.

In fact, if you know it’s a short-term thing, you can even put together your own water filter. For example, here’s a simple, virtually free option that only requires a handful of household items!

But there are other options as well.

And don’t worry. Whether you’re working with a $2000 budget or a branch from a pine tree (yes, you read that right), we’ll find a way to get you some clean water.

With each technique, we’ll also make sure to break down what water purification equipment you’ll need. Some of the options are a little more complex, while others are very simple.

And again don’t worry, we won’t have you building a huge water filtration survival system with pipes running throughout the walls of your house.

Here is a list of each technique we’ll be going over:

Many of these options are surprisingly easy too, and can be done without electricity or running water! Most just need a handful of items …and a water source.

Want to continue the journey of environmental inspiration? Why not check out our great articles on homemade mosquito repellent and febreze – For some great ways to reduce cost and exposure of harmful chemicals!

Different Ways to Purify Water: 8 Useful Techniques

You can choose from these options on how to purify your water based on what resources you have:

Technique 1. Basic Filtering of Your Water

basic filter water purification graphic

If you’re getting your water out of the tap, there is a good chance you won’t have to worry about this technique.

However, we’re putting it here on its own – and first on the list – because it is an important first step in order to do many of the following techniques.

First off, let’s dive a little bit into semantics and make one thing clear:

This technique is NOT the same as a water filter (technique #2).

The idea of initially filtering your water is simply this: to get all of the obvious, larger particles of junk out of the water before you proceed to purify or sterilize it.

This is an important part of many water purifying techniques for a variety of reasons.

For one thing, while many of these methods are aimed at killing or neutralizing things like bacteria and chemicals, they do not magically make everything disappear out of the water.

If there is dirt or debris in your water, it will remain in your water until it is physically removed.

So, how do you get the bigger junk out? Simple, really. Just strain it!

What You’ll Need

What You Need

  • Filter, cheesecloth, paper towel, bandana, or bit of cloth
  • 2 containers
  • Water

How To Do It

Fill one container with your dirty water. Then run the water through your filter and have it drip into your second container.

Don’t be shy, either! Strain the water more than once if you need to.

You should now have clean-looking water, clear to the eye and sans any dirt or debris.

However, as we’ve already established, while it may taste fine, it is possible that bacteria, viruses, parasites, and chemicals are still in there.

That’s where techniques 2 – 8 come in to play.

If you don’t have anything to strain the water with, another option is to pour it into a bowl or open container and let it sit for an hour or two, letting the dirt settle. Once the silt is at the bottom and the water is clear, you can skim any floating debris off the top and then slowly pour clean part of the water out. Just make sure to stop before any of the silt begins to pour out!

Pros and Cons


  • Gets major debris and junk out of dirty water
  • Options for ways to filter


  • Does NOT properly purify water

Technique 2. Water Filters

water filter water purification graphic

Of course, it should come as no surprise that one of the best ways to purify water at home or abroad is with a commercially purchased water filter.

These units can range in size and design from a portable survival water purification system to equipment that can service an entire house.

However, before you jump in and drop a grand or more (seriously!) on a system that claims to take every possible spec out of your water, let’s break down what we’re aiming for here.

Depending on where you are, you may not need to worry about certain things being in your water, whereas other contaminants might be a particular danger.

Look for a system that addresses the needs that you are specifically facing. Some simply filter out debris or bacteria.

Others are made especially to remove viruses, chemicals, minerals, etc. Some use carbon to filter out chemicals and bad taste, others use iodine to get rid of viruses, and so on.

Something to keep in mind is that often if a product is focused only on filtering out a handful of specific things, it will not be as expensive overall.

Nevertheless, the bottom line with filters usually comes down to convenience and qualityover cash.

They can be pricier than many of the other techniques and generally require maintenance, such as replacing filters. 

But for a dependable source of clean, tasty water on a regular basis, a good system hooked up to a faucet or the house can be the answer.

Another option for filters, especially if you’re going to be on the move hiking or camping and want a filter option, is something like a Lifestraw or Aquastiq too! These bad boys are so easy to use, you can turn a stream or pool into your own personal cup!

Finally, the one last option is making your own homemade water filter.

Whether you’re out in the wilderness or simply looking for a cool science project to do with the kids (or yourself… yes, I’m talking to you, science nerds!), a homemade water filter is a pretty sweet and easy thing to pull together.

Check out the video below for some inspiration!

What You’ll Need

What You Need

  • Your choice of commercial filter
  • Container
  • Water

How to Do It

This one centers on following the instructions that come with whatever filter you choose.

Whether it’s attaching a filter to your plumbing, screwing it onto your faucet, or plunging that Lifestraw into a creek, make sure you do it right!

Pros and Cons


  • Can create VERY clean water


  • Can be expensive
  • Can be difficult to set up

Technique 3. Boiling

boiling water purification graphic

Now we get to a classic: boiling your water.

From birth to bathing, from food to dirty dishes, hot water has been known as a cleaning (and sterilizing) agent for… well, a long time! 

And that truth holds up when it comes to drinking water as well.

What You’ll Need

What You Need

  • Heat source
  • Heat resistant container
  • Water

How to Do It

The question isn’t “does boiling purify water? but rather “how long to boil water in order to purify it?”

And the answer is simple: 1 minute.

That’s right. It’s that easy.

Simply use a kitchen stove, wood stove, camp stove or even a bonfire to bring that water to a rolling boil for a minute, and you’re good to go.

Some sources will tell you that you should make it 3 minutes if you’re more than a mile above sea level (learn more about this phenomenon here), but in reality, the pathogens will all be killed well before the water boils.

So by the time it is actually boiling, the water has already been going through the cleansing process for a while. 

Either way, boiling water is a tried and true method of purifying water.

Of course, it is also strongly recommended that, if the water comes from a dirty (or somewhat dirty) source, you take time to filter out all of the debris before you boil.

Pros and Cons


  • Excellent method to completely eradicate all bacteria from your water
  • Easy to do with minimal effort
  • Fast


  • Requires heat source
  • Requires heat resistant container

Technique 4. Iodine

iodine water purification graphic

Another classic, iodine is a great option for purifying water, particularly to get rid of those pesky viruses and bacteria.

However, be careful!

While various forms of iodine can be used to clean water, the crystal form in particular can prove to be dangerous to play around with.

What You’ll Need

What You Need

  • Iodine (preferably liquid form)
  • Container (preferably with screw on lid)
  • Water

How to Do It

Add roughly 5 drops of iodine per quart of water (the liquid form can be safely added at a 2% ratio to the water), shake it up, and leave it to work for at least half an hour.

One minor problem (though major, when you’re actually drinking it) with iodine is that the aftertaste is not good.

In fact, it’s actually quite disgusting, and that turns off a lot of users. 

However, if you want to use iodine, but find that taste just too much to overcome, a cool trick to eliminate the palate problem is adding a form vitamin C to the water (just make sure you do so after it has finished purifying!).

Another option is to use the iodine in a threaded container (one with a screw on cap, like a 2 liter soda bottle).

Once it has sat for the required half hour, hold the container with the purified water upside down and slowly unthread the cap, allowing the iodine, which should sink to the bottom, to mostly filter out first, leaving the clean water behind. 

Note: While safe for most people when taken orally, iodine is a strong chemical that can have side effects. Make sure that you’re in the clear if you’re planning on using it!

Pros and Cons


  • Portable
  • Accessible and cheap
  • Effective


  • Can have dangerous side effects
  • Makes the water taste bad

Technique 5. Chlorine Bleach

chlorine water purification graphic

Now we come to one that will turn some heads: bleach.

Once again we find ourselves questioning the premise: “Put bleach in the water… to drink it? Wait a second. Isn’t that the the poisonous stuff my parents kept out of reach so that we wouldn’t drink it?”

And the short answer is, yes. Don’t drink a bunch of bleach, guys.

Seriously. Don’t.

But a few drops? You can handle that. Right, Vizzini?

Joking aside, you really can clean up some water with a few drops of basic, household bleach. 

The stuff turns out to be just as good at killing viruses and bacteria in our water as when it’s used as a cleaning agent …that is, it’s okay when it is the right kind and used in proper doses.

So, what is the right kind?

Well, if you’re going to use bleach, make sure it is the unscented kind used for disinfection and sanitization. And make sure it has a measurable amount of chlorine.

What You’ll Need

What You Need

  • Chlorine bleach
  • Container
  • Water

How to Do It

First, it’s smart to go ahead and filter the larger impurities out of the water before you add the bleach in order to get it as clean as possible first.

Then, add the bleach.

Based off of our research (and this number varies depending on the source, kind of bleach, etc.) you can generally put roughly four or five drops of bleach in each quart of water you need cleaned.

However, try to do some independent research on the specific kind of bleach you have before committing to a bleach to water ratio.

You will want to know what concentration of chlorine is in the bleach, as this can vary. Use the chart in this article under the section “Purifying by adding liquid chlorine bleach” as a guide.

Once you’ve filtered the water and added the bleach, shake it all up and then let it sit and do its purifying thing for at least an hour (some sources say a half hour, but an hour is a safer bet).

Pros and Cons


  • Very effective way to purify water
  • Minimal effort


  • Care must be taken not to over-add bleach

Technique 6. Ultraviolet Light


Okay, this one is pretty cool. Believe it or not, you can actually clean water by using ultraviolet light (and that is just one of the TWO light-driven purification techniques on our list)!

What You’ll Need

What You Need

  • Waterproof ultraviolet flashlight
  • Container
  • Water

How to Do It

Apart from obtaining an ultraviolet light that suits the needs of this technique, it’s pretty simple, straightforward, and quick.

This time it is imperative that you properly filter the water before using the light.

The water cannot be cloudy at all if the technique is going to work properly, as it will hamper the light’s ability to shine through the liquid and kill the bacteria.

Once the water is clear, simply drop the flashlight into your water and swish it around, allowing it to kill the bacteria in a matter of minutes!

Now, unfortunately, this method does have some drawbacks.

For one thing, it only deals with bacteria in the water.

On top of that, purifying agents like bleach and iodine remain in the water, combating pathogens for a long time – but this is not so with ultraviolet light.

Once it’s removed, the light stops doing its thing, and any leftover bacteria remains ready to wreak havoc on your digestive system.

Pros and Cons


  • Quick and simple
  • Doesn’t taint the taste of the water


  • Requires a specific kind of flashlight
  • Is not as thorough as other methods
  • Only deals with bacteria

Check out this article if you want to see a more detailed breakdown of the pros and cons of the ultraviolet water purification technique.

Technique 7. The SODIS Method

simple solar water purification graphic

Now we come to the other light method, and a technique that sounds like it came straight from a science text book (…or a Marvel comic).

Don’t get intimidated though, it turns out to be way less complex than anything we’ve talked about so far.

SODIS simply stands for Solar Disinfection, or the solar disinfection process.

How It Works

Water in a plastic bottle traps the heat of the sun and heats up, while the UVA rays help to zap the bad stuff.  However, this can have some side effects too (more on that below).

What You’ll Need

What You Need

  • Sunlight
  • A clear, smooth plastic bottle
  • Water

That’s it.

How to Do It

The process is even easier than the name.

You simply fill the bottle with clear water (run it through your filter until it’s as clean as possible), put the cap on tight, and leave it in concentrated sun for several hours – ideally six, at a minimum.

The key here is “concentrated sun,” meaning don’t use a bottle larger than one or two quarts. Also, make sure the bottle is clean!

Now, this method can be a bit restrictive, geographically speaking. Many places do not get six hours of strong sunlight on a regular basis.

But if you happen to live in an area of the world where this is the case, you can use this long but hassle-free method, and leave the sun to do all the work!

The glaring issue here, if you hadn’t already noticed – is that heating up water in a plastic bottle can have some pretty nasty side effects.

Leaching chemicals in particular can make this a less-than-desirable option. 

However, if you’re desperate for water, have some powerful sun, and are willing to risk chemicals over parasites and diseases, this is a legit option!

Here’s a bit more info on this “less-than-sci-fi-ish” technique!

Pros and Cons


  • Simple process
  • Easy to get supplies for


  • Dependent on cleanliness of water a while
  • Can take a while
  • Uses a plastic bottle that can lead to leaching

Technique 8. Pine Trees


At long last we come to the pine tree method hinted at in the beginning. And yes, this really is a legitimate way to clean water!

If you ever find yourself really, truly stuck without the forms of water purification already mentioned, all is not lost.

Even if the fire has died out, the water filter has run out of cartridges, the iodine and bleach are gone, the sun has gone down, and the ultraviolet flashlight has run out of batteries, there is still one more method available that is as basic as it gets.

What You’ll Need

What You Need

  • Small pine branch or stick
  • Container/bottle
  • Water
  • A small tube and fastener (optional)
  • Filter or cheesecloth (optional)

How to Do It

Just take your pine branch, peel it, put a piece in the tube and fasten it, allowing the water to run down the tube and make contact with the branch as it drips through the filter and into your container.

Some simpler versions of this method just have you pour the water over the stick right in the bowl, though this may not be quite as thorough.

This method can remove as much as 99% of the bacteria!

It uses the xylem tissue in the plant as a natural water filter, capturing particles and giving you some impressively purified water.

A team of researchers at MIT recently discovered the method.

Check it out!

Pretty wild, huh? And so simple.

When all of the human-made options and contrivances fall short, it never hurts to look to nature to provide a simple and effective solution.

There’s almost always one out there.

Pros and Cons


  • Affordable
  • Effective
  • Accessible


  • Can take a while

The Importance of Clean Water

So there you have it: an awesome list of water purifying options available at a fairly low cost, and doable with easy-to-find supplies.

Now you have no excuse to contract an infection, virus, or any other sickness from chemicals, sewage, etc. in connection with your drinking water!

These methods are not rocket science, and they are often quick to implement.

Not only that, but none of them are seriously dependent on electricity or anything else you couldn’t have readily available on a small, sustainable homestead. 

Okay, we’ve gone through the list and broken down the options. Now it’s your turn.

Pick one and try it out for yourself (come on, you know you’re dying to know how bad that iodine technique really tastes)!

Comment with feedback on how it goes, and please, please, please share the article! Let’s spread this knowledge around as much as possible!

Knowledge is power, and the simplicity of these solutions can help countless people around the globe who are dealing with contaminated water issues on a daily basis.

You can also use this information to help take your commitment for truly sustainable living to the next level, resting in the comfort that whatever emergencies come your way, at least contaminated drinking water won’t one of them!

glass of water

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