How to Purify Water in 10 Easy Ways

Every organism on earth relies on water for survival. 60% of the human body is water, so it’s really no wonder that we can only last three days without it. Fortunately, there are a lot of ways to find water in emergency or survival situations. Unfortunately, finding a source is just half the job.

Even when appearing clear, water can still be full of harmful microorganisms that can give you a variety of nasty diseases. This is why it’s important to know how to purify water before consuming it.

Here are 10 different ways to make water safe to drink:


how to purify water through boiling

The first method of purifying water is by boiling it. The US Environmental Protection Agency says you must bring water to boil and keep it boiling for at least a minute for it to be purified.

The higher the altitude, the longer you should keep it boiling. For instance, in altitudes above 5000 ft., you should keep it boiling for 3 minutes.

Boiling is one of the easiest and safest ways to purify water. It’s also the least expensive and it’s something you can do even when you’re down to the barest resources. Boiling can kill bacteria, parasites, and other harmful microorganisms in the water. If you suspect contamination of your local water source, boil it first before consuming it.


filtering water makes it safe to drink

Filters work by physically straining the water to remove various impurities.

If the water looks cloudy, filtering can be done before boiling to take the debris out of it. While filtering can get floaties, bacteria, and some parasites out of the water, it doesn’t do much for viruses. They can also be bulky and more expensive than other means of purification. The upside is once water is filtered, you can drink it right away.

DIY Biofilters

One way to purify water in a pinch is by making your own biofilter. Biofilters usually involve the use of gravel, sand, and activated charcoal. The idea is to let water pass through these natural filters to strain bacteria, parasites, and other nasties — the lower it goes, the finer the strain becomes, the cleaner your water would be.

These filters can be big enough to produce gallons of water in a day, like this one; or it could be a handy biofilter made of PVC pipes.

Survival Straws

Commercial filters like survival straws are pretty popular because they’re handy when you are on the trail or caught in a survival situation. They’re light and portable, so you can keep them in your emergency kit or bug out bag. You’ll be able to drink directly from the source. Survival straws like LifeStraw claim to get rid of 99.99% of contaminants, including E. Coli and Giardia. They don’t work with salt water, though, so only use it on freshwater sources.

Solar Disinfection

You can’t discount the sun’s power when it comes to purifying water. Solar water disinfection (SODIS) works by exposing a clear bottle of water to direct sunlight for 12-24 hours.

On cloudy days, the water bottle is exposed for 48 hours. This harnesses the power of the sun and natural UV rays to kill bacteria. You obviously can’t use this method when it’s raining (you can catch rainwater instead, though), but this could very well save you from dehydration in cases where you’re exposed to a lot of sun.

Handheld UV Devices

If you can’t use UV from the atmosphere, you might be better off purifying water with the UV in your pocket. Handheld UV devices are available and can effectively treat water by “zapping” the microorganisms in the water. The device is light, the treatment is quick (all done in about 2 minutes), and it leaves no aftertaste in the water. The downside is that it’s battery-powered and pretty pricey.

Chemical Treatment

hand holding a water purification tablet

Iodine and chlorine are used to purify water and make it safe for drinking. These are very handy; they come in portable bottles or tablets that you can carry around your kit, so they’re ideal in survival situations. They also don’t need special procedures or fuel to treat the water.


Iodine has great disinfecting properties: you can use it to dress minor injuries and to purify water. Iodine comes in tablet and tincture forms. The downside to using iodine is that you have to wait for at least 30 minutes before you can consume the water. It also leaves a nasty aftertaste, so it’s handy to carry around vitamin C tablets or a powdered juice mix to help with the taste. Pregnant women and people allergic to shellfish would have to stay away from this method, though.

How to Purify Water Using Iodine

With the 2% tincture, you can use five drops of iodine for every quart of water. It should sit for about 30 minutes before you can drink it — longer if the water is cloudy.

For tablets, you can use 1 or 2 tablets for every quart. You have to wait for the tablets to dissolve and again, wait for 30 minutes for it to kill all the nasties.


When staying home becomes unsafe, bugging out could be your only shot at survival. Make sure nothing goes wrong.

Download our FREE guide on HOW TO BUG OUT SAFELY and learn how to idiot-proof your bug out plan now.


If you have iodine restrictions, you can use chlorine tablets for purifying water instead. Chlorine tablets work pretty much the same way as iodine tablets. You can use one or two of these tablets to treat your water. Just wait for them to dissolve and let them sit for about 30 minutes. Water treated with chlorine will have a longer shelf life. You can also get rid of the aftertaste and smell by letting it sit uncovered for a few minutes so the chlorine can evaporate.

Household Bleach

Household bleach contains chlorine, so you can also use it to purify water. But you have to be careful: you should only use regular, unscented bleach that has been stored for less than a year. Don’t use bleach with additives like perfumes, additional active ingredients, and color-safe properties. 6 drops of household bleach can pretty much do the trick to a gallon of water. Let it sit for 30 minutes.

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