people drinking water

What Is the Best Way to Purify Water?

Most people know that 75% of our bodies consist of water. Most people know that drinking water is vitally important to life. And most people know how and where to find clean, purified water. But what if you don’t have access to clean water? What if you live in a place where clean water isn’t everywhere, or what if you get stranded somewhere that doesn’t have grocery stores and bottled water? Or what if a nuclear or natural disaster hits and you have to find clean drinking water on your own, with no way to simply purchase some from a store?

people drinking water

Knowing how to purify water could save your life. Not only is water essential to our survival, but it is also essential to our ability to thrive and remain healthy. Water plays a multitude of roles in keeping our bodies functioning properly. It helps regulate body temperature, protects your organs, helps dissolve nutrients so your body can use them, carries oxygen to cells, aids in flushing out waste products, and lubricates joints and tissues surrounding mouth, eyes, and nose.

The Importance of Water

Water is so vital to life that people cannot live more than 3 to 5 days without consuming it. Some studies have shown that people have lived up to a week without water, but those individuals were likely overhydrated before they discontinued consumption of water. If you’re prepping for a disaster or are journeying into the wilderness for a substantial period of time, preparation is absolutely essential to ensuring you are not without water.

African water holeBob Metcalf

Before we get into the basics of the best way to purify water, we need to understand the difference and important of filtration and purification. Filtration is used mainly to remove impurities (mainly chemical ones, such as chlorine, copper, mercury, lead, magnesium, iron, and more). Purification, however, is used mainly to remove bacteria and viruses. If possible, it is best to both filter and purify your water, but in an emergency situation, you may only be able to do one or the other. Being prepared to do both will help you secure a long-term water supply that is large enough to sustain a larger group of people.


As mentioned above, filtration is primarily used for removing chemical impurities from water. Many filters will inhibit the growth of bacteria, but they should not be the only thing used to ensure your water is safe to consume. Generally, filters are porous to allow water to pass through them. The most common types of filters are activated carbon and ceramic.

Mechanical Filtration

Mechanical filters remove dirt, sand, gravel, and other sediment from water. While they don’t generally help with chemical removal or bacteria, they are good to use as a starting point in creating safe, drinkable water. If the water you’re filtering is heavily contaminated with visible sediment, it is best to use multiple filters with varying coarseness, increasing in fineness, until the desired result is achieved.

How to Filter Water with Cloth

If you find yourself in a situation with little to no options when it comes to drinking water, filtering water with cloth is a very viable option. While it will not result in perfectly safe drinking water, it is a great first step in creating safe water and it can definitely be used in emergency situations to make fresh water a bit safer to consume. To filter water in this way, you should begin with a clean piece of cotton or nylon fabric.

Using a dirty piece of fabric can introduce more contaminants and will likely do more harm than good.

Depending on the size and thickness of the fabric you have, it can be folded over to create more filtration for the water. You simply have to pour the questionable water through the cloth and into some type of container, and you’re one step closer to having uncontaminated drinking water.

Filtering water with cloth has shown to reduce the risk of cholera by 50%, in addition to effectively removing all zooplankton, most phytoplankton, and other particulates of a certain size. Additionally, cloth filtering is somewhat effective at removing turbidity and bacteria and is somewhat effective at improving taste, smell, and color of the water.

Filtering water with a cloth, however, will not remove viruses or chemicals from the water.


While some freshwater sources produce water that appears clean and safe, you should not assume that any water that comes from a natural source is not safe to drink. While you may need to filter water first before purification, if it appears clean


Many people consider boiling water to be the safest method of purification. The key to this method, though, is knowing how long to boil it to purify it. The Wilderness Medical Society states as soon as water hits the boiling temperature of 212° F or 100° C, all pathogens will be killed, regardless of how contaminated the water was and at what altitude you are. It is important to note that while boiling will kill or remove microorganisms in the water, it will not rid the water of chemical contaminants.


The process of distilling water involves condensing water vapor or steam, generally from impure water, to make it suitable for drinking.

The best way to distill water is to put the unclean water in a pot over fire or a burner of some sort. Place a bowl or other type of collection container on the top of the water with a pot lid upside down above that. As the water heats up (it should not boil but it should come close), the condensation will collect on the top of the pot lid and drip into the collection bowl. The water in the collection bowl is distilled and ready to drink!

You can also purchase a survival water distiller to have on hand in an emergency. It should be noted that while distilling water in extreme circumstances is okay, regularly drinking distilled water is not a good idea due to the acidity and lack of minerals in distilled water.

Commercial Purifiers

If you’re planning ahead to have to purify water in a survival situation, a commercial purifier is a great option. Essentially, water goes into a hose or straw, through a filter (likely ceramic or charcoal), and comes out into a container or through another hose ready to drink. A water filter straw is a great option for survivalists or preppers who want clean water quickly and easily. Water filter straws an be used with any water as they contain a filter (and maybe more filtration equipment) that immediately purifies water and makes it safe to consume.

UV Light

You can purify water with UV light using one of many UV water sterilizers. UV purifiers are very fast and effective—most of them can purify 32 ounces in just 90 seconds, and there is no wait time after purification before the water can be consumed. UV water sterilizer pens are the most common type of UV purifiers for survivalists and preppers, as they are small and very efficient and effective.

While UV light purification generally refers to using a UV water sterilizer, you can also purify water with sunlight. It takes significantly longer, but it is free and 99.999% effective at removing various bacteria, viruses, and parasites. To purify water with sunlight, put clear water in a clear plastic bottle (no larger than 2 liters). The bottle should be laid flat, preferably on a reflective surface. If the sky is mostly sunny, it will take 6 hours to purify the water with sunlight. If it is partly cloudy or mostly cloudy, it will take 2 days to purify the water, regardless of the temperature.

Chemical Purification

While chemical purification is not the first choice of most individuals, it’s a good backup and a great way to purify large amounts of water easily and relatively quickly.


The use of chlorine in water purification is effective, provided that it is done correctly. Sodium Hypochlorite is the active ingredient in bleach, which is a source of chlorine, making bleach a great way to use chlorine in water purification. Make sure you’re using regular bleach with no dyes, scents, or additives. To purify water with bleach, you need to remember the ratio of 2 drops of bleach per 1 quart of water. After purifying, you need to wait 30 minutes to drink the water.

If your water is murky, filter is beforehand and if it’s still not completely clear after filtering, double the amount of bleach and the wait time for purification. Be sure to slosh the bleached water around a bit during the wait time, and make sure you also get the lid of your drinking vessel wet with the purified water as well so that you don’t recontaminate the newly purified water.


Using iodine to purify water is considered to be more effective than the use of chlorine. However, iodine affects the taste of the water and the effectiveness declines when the water is exposed to sunlight. Liquid iodine and iodine tablets are the most common ways to use iodine to purify water.

Leave a Comment