How to Filter Water


Water is a basic necessity you can’t survive without. If you’re out in the wilderness whether it’s fishing, backpacking, kayaking, hunting or just camping, one necessity you can’t forget to pack is pure drinking water. But, what if you didn’t carry any water during your outdoor excursion? Well, you’ll probably have to find a source of fresh water to drink. In such a situation, having a solid understanding of how to filter water will really help out as some water sources may not have clean water to drink.

There are many methods you can use to purify water from boiling, decanting, distilling, filtering, to using ultraviolet methods. However, the first thing you need to do before you employ any of these methods is to filter out the visible sediments.

So, having mentioned that, this short guide will now discuss seven common methods that can be used to purify water to guarantee your survival in the wilderness.

But First, What’s the Importance of Filtering Water?

Well, there are many reasons why you’ll need to filter and purify water. For instance, in a situation where all the basic necessities such as water and food are not available, then the knowledge of self-sufficiency will be critical. One of these is purifying your water.

If you’re in the wild, drinking water from running steam before treating it first can be very dangerous. That’s because the water might be contaminated with viruses, chemicals, bacteria, and other pollutants. Such pollutants can cause illnesses such as Cholera, Typhoid Fever, Giardia, or Dysentery that can cause serious illness or even death.

Now that you have a basic understanding of why you need to filter water, let’s now go to our main topic which is filtering water to purify it.


How to Filter and Purify Water

1. Boiling Water to Decontaminate it

This is one of the oldest and well-known methods of purifying water. It’s also the safest method that works in any situation whether it’s camping, backpacking expedition or maybe if you fear your local municipal water supply is contaminated. For the case of a camping expedition, boiling water is a cheaper alternative as compared to buying bottled water.

But, How Should You Boil Your Water?

Well, the first thing you need to do is to ensure the water doesn’t have any sediments or leaves on it. If the water is too cloudy, you can simply allow it to settle then pour it in another container without disturbing the sediments at the bottom.

Alternatively, you can filter the water using a clean cloth, a bandana or a t-shirt to remove any debris particles. When the water is clean, then you can proceed to boil it.

Now, boiling water isn’t a difficult endeavor. According to the Wilderness Medical Society, heating water to a temperature of 160°F for 30 minutes or 185°F for 5 minutes is one efficient way of having clean safe water to drink.

If you’re a prepper in the wild, a solar cooker is a smart option you can consider to heat your water. If you’re in a high altitude region (above 6,500 ft), then you have to let the water boil for a bit longer to make it safe for drinking.

When the water has cooled naturally, you can store it in a clean container then cover it to prevent any contamination. In case you’re not impressed with the flat taste of the water, then you can try to improve the taste by adding a pinch of salt in each liter of water or try pouring the water from one container to another several time.

Now, although boiling water does kill bacteria, it doesn’t entirely eliminate other contaminants such as heavy metals. In such a situation, the next water purification method might help.


2. Disinfecting Water Using a Bleach

In case the situation doesn’t allow you to boil water, then you can try disinfecting it using bleach. First, this method is quite easy to accomplish when you’re in the wild and second, it’s an effective method that eliminates water contaminants as compared to boiling.

So, to disinfect water using bleach, the first thing you need is to ensure that the active ingredient in your bleach is Sodium Hypochlorite (NaOCl) with a concentration of 5.25% to 8.25%. You may find some bleaches that use Sodium Hydroxide instead which is also safe.

Just make sure the bleach doesn’t contain any scented additives. You can do this by sniffing your water just to be sure. Remember, most municipal water systems use chlorine to purify their drinking water. That makes this method an effective way of filtrating and purifying your drinking water.

So, Here’s the Process

When disinfecting water using bleach, there are lots of ratios and percentages you’ll need to adhere to as well as confusing terms such as per liter, gallon, cups, quartz, drops, and ml. Thankfully, when you’re in the wild, all you need is this simple procedure.

  • First, grab a small piece of toilet paper and place it inside a bottle cap. Fill the cap with the bleach then allow the ‘toilet paper wick’ to hang slightly.
  • Tilt the cap slightly at an angle to allow the bleach to flow in steady consistent drops that are easy to count.
  • Alternatively, you can pack a clean dropper in your medical kit to use during this process. A dropper is easy to use as you only have to press the top to drip the bleach in steady drops.
  • Mix the water thoroughly then allow it to settle for 30 minutes. At this time, the water should have a slight chlorine odor when you sniff on it. In case it doesn’t, then you can repeat the procedure and this time, add about 4 drops of bleach per liter of water.
  • Also, you need to ensure the water temperature is slightly higher above 60° Otherwise, if the water is cold, then your bleach might fail to work. Actually, this was confirmed by a report that detected traces of Giardia particle in cold treated water. This simply means that cold water is less effective in chemical treatments such as bleach, iodine, and calcium hypochlorite.


3. Purifying Water Using Iodine

When you’re in the wild, water sources can carry bacteria such as giardia, which can be harmful to your health. If you’re already aware of this, carrying too much stuff to purify your water can be strenuous.  In this case, the easiest, smartest, and most affordable method of purifying water is by using iodine. Iodine is available in tablets, drops and crystalline forms.

So, to purify water using iodine, you’ll need two water bottles, iodine (in the form of tablets or drops) and an eye dropper.

  • Step One: The first step is to locate a clean source of water most preferably from a flowing stream/river rather than stagnant water in a pond or pool. You should also check the area to ensure there are no pesticides or weed killers flowing to the river. At least this way, you’ll be able to reduce the number of harmful chemicals and microorganisms in the water.
  • Step Two: Cover the mouth of the bottle with a piece of cloth, t-shirt or bandana to prevent floating particles from entering inside the water.
  • Step Three: If you’re using liquid iodine, carefully use a dropper to squeeze about 5—10 drops of iodine per 1 liter of water or 32 fluid ounces. If you’re using tablets, then adding one tablet to a liter of water will suffice.

Now, the amount of iodine you’ll need to add to your water will vary greatly depending on the water clarity. If the water is clear, adding 5—7 drops will do. If it’s cloudy, then 10 drops will be fine.

  • Step Four: Once you’ve added the iodine, allow the water to sit for about 30 minutes. Remember, iodine is effective when it’s used in warm water rather than cold water. So, once you’ve applied the iodine, you can take a quick hike to admire nature before the treatment takes effect.

Now, before you can enjoy your water, you need to understand that iodine treatment isn’t meant for everyone. Pregnant women, people with thyroid problems, women above 50 years and those allergic to iodine should not drink such water.

Also, some people may not be tolerant to the taste of iodine in their water. So, in this case, masking the iodine will be necessary. You can do this by;

  • Aerating the Water: Simply by shaking the water bottle vigorously or simply by pouring the water from one clean container to another.
  • Adding an Energy Drink: Another method is adding a powdered energy drink to your water then shaking the bottle vigorously. By the way, this is one of the most common strategies used by most campers and backpackers.
  • Neutralizing Tables: In most cases, iodine tables come with neutralizing tablets all in one package. After treating your water, and leaving it for 30 minutes, you can add one neutralizing tablet to mask the iodine taste.


4. Using Water Filters

Filtration is a highly common method of purifying water in the wild. It’s usually applicable when the only source of water is muddy, cloudy or very dirty. Even when you’re using another purifying method, filtering your water is the first step. So, how do you filter your water?

  • Step One: The first step is to lay down your requirements. Here, you’ll need two containers, a piece of cloth, charcoal, gravel, and sand.
  • Step Two: Try to make an improvised filter system by cutting the bottom of a bottle to create an opening. You can achieve this by placing the bottle upside down then creating small holes at the bottle’s cap. This will allow water to drip into the next collecting bottle.
  • Step Three: Now that you’ve improvised a filtration system, the next step is to make the filtration unit. Start with the piece of cloth (preferably made from cotton fabric) and place it on the mouth of the bottle.

Next, place a layer of charcoal on top of the cloth. You can obtain this from the fire you had made earlier. Charcoal is a powerful natural absorbent that can get rid of toxins and odors via a chemical reaction.

Add sand on top of the charcoal. Sand will help to eliminate both large and microscopic particles from the water.

Finally, add stones and gravel on top of the sand. Stones won’t filter any particles but rather, their work is to dissipate the flow of water to allow it to spread out over the entire treatment bed. Additionally, stones and gravel will trap larger particles that will not manage to penetrate through the spaces.

If it’s possible, it’s a good practice to add another layer of sand on top of the gravel then another layer of small stones on top of the sand. This way, you’ll have a double layer of sand and stones/gravel to guarantee efficiency.

  • Step Four: Now that you’ve filtered your water using your improvised filtration system, the next step is to eliminate pathogenic organisms and heavy metals.

Remember, filtering alone doesn’t remove all of the bacteria and harmful organisms. You need to combine this method with another effective purification process to guarantee efficiency. But, there’s a way you can purify water by filtering and make it safe for drinking.

  • Using a Portable Water Filter: Portable water filters have been a long-standing solution for preppers and backpackers due to their efficiency and their small sizes. They contain carbon and other filter elements to remove bacteria and other chemical contaminants from the water.

Modern portable filters come with reusable filters that eliminate the hassle of having to replace them with new ones and can filter particles as small as 0.2 microns in size.

  • Filtration Pump: Another method you can consider once you’ve filtered your water, is using a filtration pump to remove chemicals from your water.

A filtration pump is simply a hi-tech bottle that lets you squeeze contaminated water through a ceramic or charcoal filter to treat it.


5. Exposure to Sunlight

Also known as ultraviolet light or solar water disinfection, (SODIS), this method of purifying water is commonly used in the wild especially in sunny regions that record very high temperatures. How does it work anyway?

It’s pretty simple. This method uses the ultraviolet rays from the sun to kill the DNA of bacteria in your water to make it safe for drinking. The method has, in fact, been confirmed by the World Health Organization as a safe process for purifying water.

  • Step One: If you’re in the wild, the first thing you’ll need is a clean source of water. If you’re at home, tap water will do especially if you’re doubting it has been contaminated. In case the water is cloudy, you need to filter it thoroughly using our previous method above to remove any visible debris.

Note: The water you’re using must not be chemically contaminated whatsoever. That’s because this process only removes bacteria but not chemicals in your water.

  • Step Two: Find a clear water bottle (s) no longer than 2 liters. The bottles should be crystal clear with no scratches, colors or labels on them. Opaque bottles (including glass bottles) can block UV rays from penetrating making this method quite unsuccessful.
  • Step Three: Fill the bottles with water about halfway full then shake it vigorously. This way, you’ll saturate the water with oxygen making it easier to kill the germs. Fill the water to the brim then expose the bottle to the sun.

For more efficient and fast results, lay the bottles on a reflective surface to allow UV rays to penetrate deeper.

  • Step Four: If the day is sunny, you can allow the bottles to sit for about 6 hours before you can drink the water. In case of a cloudy day, this can take up to 2 days.


6. Purifying Water by Distilling

Whether it’s at home or in the wild, distilling water is another method that can really help to eliminate contaminants such as bacteria, heavy metals and other impurities from the water. The best thing about distillation is that it allows you to decontaminate any type of water including salty ocean water.

Note: When heating water during the distillation process, you should avoid boiling water to extremely high temperatures. By doing so, you might accidentally achieve the boiling temperature of certain undesirable elements causing them to vaporize and re-contaminate your already distilled water. So, with that said, here’s a simple process you can use to distill your water.

  • Step One: You will need a deep pot, a glass bowl that floats, a metallic lid, and a source of the fire.
  • Step Two: Place the pot on the fire and add the contaminated water inside about ¾ full. Place the floating glass bowl inside the pot then cover the pot with your metallic lid. Ideally, the lid should have a concave shape to hold ice cubes on top.
  • Step Three: Cover the pot with the lid (with ice cubes on top) then heat the water. As the water boils, it will create condensation on the lid which will then flow as small droplets inside the glass bowl inside. If you’re in the wild and there are no ice cubes, you don’t need to worry as you can just cover the pot with an empty lid. After all, the ice cubes are just for speeding the condensation process.
  • Step Four: Once you’re certain the glass bowl is full and might sink, remove it gently and drain the condensed water in a clean bottle for storage. Distillation removes oxygen from the water. For this reason, most people complain that distilled water is tasteless.


7. Sedimentation

If there’s a water purification method that’s often overlooked, then it’s the sedimentation process. You see, it’s not always that the water you need for drinking will be crystal clear. There are other times when water appears to be extremely muddy. During such scenarios, sedimentation becomes the only realistic method to consider. So, how do you accomplish this?

  • Step One: The first step is to prepare two containers where you’ll have the water.
  • Step Two: Next, fill one of the containers with dirty water and allow it to rest for about a day or two.
  • Step Three: After all the sediments have settled at the bottom of the container, pour it in another container slowly to avoid disturbing the dirty particles at the bottom.
  • Step Four: Once the water clears, you can now consider other purification methods such as filtration, boiling, distillation, or use of chemical processes to remove bacteria.


8. Using Plants

Yes! You heard me well. Although it’s surprising how certain plants have the capacity to decontaminate your water making it safe for drinking. In the wild, there are many types of plants available. However, you need to be really careful as some plants are extremely toxic and cause serious health problems.

So, to prevent any problems, here are some plants that you can consider.

  • Banana peals
  • Fruit peels
  • Oregon Grape
  • Plant Xylem
  • Jackfruit seeds
  • MolingaOleifera
  • Reeds and bulrushes
  • Cilantro

Now, there are two ways you can enjoy purified water using plants. The first one is to collect fresh leaves from these plants then wrap them inside a plastic bag. The water from the leaves will condense creating enough water to drink.

The next method is to use some of these plants’ leave to purify your water. Oregon Grape has some of the best leaves that contain natural berberine which is an antimicrobial alkaloid.

Since Oregon Grape is quite difficult to find in tropical regions, coconuts and citrus fruits are perfect alternatives that can work out. Here, you only need to add these plants in your water and wait for it to be purified.


Final Note

In conclusion, purifying your water in the wild is one of the most important survival skills you should be aware of in case you’ve found in a water crisis. You see, you can spend several weeks without food, but without water, you can only survive for days.

That makes water a critical component for human survival especially if you’re out in the wild. Therefore, having some of these water-purifying methods is critical for your survival as you only need to use one or combine two or three methods at once if you’re not certain one method will work.

So, with that said, the next time you suspect the water you’re drinking is contaminated with pathogens, microorganisms, or harmful chemicals, then you know what exactly you’re supposed to do.

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