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Best Survival Water Filters and Purifiers

Best Survival Water Filters and Purifiers post image

Water is by far the most important thing you need for survival. It isn’t just access to water which is important, it is access to clean water. To give you an idea of how important water sanitation is, diarrhea is responsible for 4% of all deaths worldwide – and most cases of diarrhea are caused from drinking dirty water. If you are in a survival situation, the last thing you want to do is drink unsafe water and end up with diarrhea or water-borne illnesses. Even if water looks clean, it could still contain many pathogens. You must clean your water before drinking it!

What to Look for in a Survival Water Treatment System

Before I get into all of the qualities to look for when buying a survival water treatment system, I want to point out that store-bought filters aren’t the only way to purify water to make it safe for drinking. Read this post to learn ways to purify water without a filter, including using bleach and making your own water filter.

For a water treatment system to be practical for survival is must:

1. Remove Disease-Causing Agents

There are plenty of cheap generic water filters made by Chinese companies that you can buy online. Please DO NOT BUY THESE. They are often made from inferior materials and do not remove harmful substances. Very few of those cheap water filters have actually been tested, so there is no guarantee that they will remove the harmful substances they claim to. It is worth it to pay a bit more and get a survival water filter which will actually give you clean water.

The three types of pathogens you need to worry about are:

  • Protozoa: These are the most common types of pathogens in water and cause backpackers a lot of grief. The two big ones are Giardia and Cryptosporidium.
  • Bacteria: Bacteria are fairly large, so they are fairly easy to filter out. Examples include E. coli and Dysentary.
  • Viruses: When backpacking in the back country, viruses aren’t too much of a concern. But if need to treat water in the city or in a third-world country, then it may contain viruses like Hepatitis A and rotovirus. Most water filters do not strain viruses!

2. Be Lightweight and Compact

When you have to carry all of your survival gear on your back, then every ounce matters. If you are packing a family Bug Out Bag, then you will be distributing the gear so you can afford to carry a larger water treatment system. Otherwise, I opt for the lightest and most compact system.

3. Be Long-Lasting

When buying survival water filters, pay attention to how many gallons the filter is rated for. In a SHTF situation, you won’t be able to go online and buy replacement filters.

Water Filter vs. Water Purifier

Note that there is a big difference between a survival water filter and water purifier. With a water filter, there is a physical medium (such as ceramic, silica, fiberglass, or a structured matrix). The water is pushed through the medium, which strains pathogens out of the water. The smallest bacteria are about 0.2 microns, so the water filter should be capable of straining at least this size.

With water purifiers, chemicals or UV light is used to kill viruses, as well as bacteria and protozoa. I repeat, in the wilderness, you usually don’t have to worry about viruses in water. But, in cities and third-world countries, there may be viruses in the water.

survival water filter

No Water Treatment System is Perfect!

Unfortunately, there is no survival water treatment system which is perfect for treating all types of pathogens, and in all situations. You may want to pack multiple types of survival water treatment systems to cover all of the bases.

Water Filters Remove bacteria and protozoa, but don’t remove viruses.

Chemical Water Purifiers: Kill bacteria, protozoa, and viruses. However, the water may need to sit for a long time before certain viruses or bacteria are killed. You need one tablet/drop for each batch of water, so you will run out relatively quickly. These usually add a bad taste to the water.

UV Water Purifiers: Destroy bacteria, protozoa, and viruses by scrambling their DNA. But, if you let the purified water sit too long, the DNA may unscramble and the organisms can reactivate!  UV water purifiers also won’t remove sediment and particles from the water, and rely on batteries to power them.

My Favorite Survival Water Treatment Systems

There are hundreds of different water filters and purifiers on the market (usually marketed for ultra-light hikers). These are just a few of the ones that I have tried and like. Feel free to let me know of any that you tried and liked!

Sawyer Mini

water filter for bug out bag

This is the water filter that I take when going backpacking with my family, and I’ve got it in my Bug Out Bag. It won’t treat viruses, but is a great option for backcountry survival where viruses aren’t likely to be an issue. The reasons that I like it are:

  • It can be used in multiple ways. You can use it as a straw and drink directly from streams or even puddles. You can screw it onto a water bottle. Or you can put dirty water in the pouch and squeeze it through the filter into your water bottle.
  • It is VERY SMALL and LIGHTWEIGHT. As far as weight and size goes, you won’t find an option much better than this!
  • It lasts for 100,000 gallons. Basically, that means it will last for forever.
  • It is very easy to use. It took my 4-year old all of 5 minutes to figure out.
  • It is cheap. Especially since you don’t ever have to buy any replacement cartridges.

The only thing I don’t like about the Sawyer Mini is that it does take a while to squeeze water through it to fill all of your water bottles or cooking pots. Also, the pouch which comes with it got a hole in it really quickly, so I had to improvise. You can read a more complete review of the Sawyer Mini here.

Aquamira Water Treatment Drops

survival water purifier

I also keep a bottle of these in my Bug Out Bag in case I have to treat any really dirty water which may have viruses in it. The reasons I like this system are:

  • Really lightweight and compact. This makes it easy for me to carry multiple bottles of it.
  • Effective on viruses. Though note the water does have to sit a while before you can safely drink it.
  • A bottle of the drops only costs about $15, so it is a lot more affordable than many other purification systems.

SteriPen Water Purifier

steripen uv water purifier

This is a UV water purifier, so it will require batteries to operate. All you have to do is put the pen into the dirty water and push a button, and it will purify the water instantly (for really dirty water, strain through a bandana first).   Some of the reasons I like it are:

  • Very lightweight and compact.
  • Guaranteed for 8,000 treatments. That should hold you over for a while in a survival situation!
  • Kills viruses. This is what I will use when going to third-world countries.

Because the SteriPen uses batteries, it isn’t as reliable. I keep this one at home in case the grid goes down and I need to treat city water. It definitely beats bleach as a purification method!

Image credits:
Pumping water from a reliable source by Chris Waits, Found on Flickr; CC BY 2.0
Natalie and Alison Filtering Creek Water by John Mundy, Found on Flickr; CC BY NC ND 2.0

What water treatment system do you plan on using for SHTF survival situations?


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