Best Water Filter – How They Work and Where to Get One


Even if you’re never in a survival situation, the best water filter is something you should own. Unclean water accounts for 2 million preventable deaths yearly. Water filters save lives. It’s as simple as that, so keep reading.

The average human can survive three days without water. Water is second only to oxygen in the list of things we need to live. But, it’s far too easy to assume that clean, potable water will always be a faucet-turn away.

It goes without saying in an emergency, drinking water is vital. You can’t expect clean tap water at your fingertips. You also can’t carry all the clean water you need to survive. That means you need a good water filter.




How Water Filters Work

Propel Powder Packets 4 Flavor Variety Pack With Electrolytes, Vitamins and No Sugar 10 Count (Pack of 5) (Packaging May Vary)
25,760 Reviews
Propel Powder Packets 4 Flavor Variety Pack With Electrolytes, Vitamins and No Sugar 10 Count (Pack of 5) (Packaging May Vary)
  • Contains five (5) 10-count boxes of Propel Powder Packets Raspberry Lemonade (1), Berry (1), Grape (2), Kiwi Strawberry (1) with Electrolytes, Vitamins and No Sugar
  • How Gatorade does water, with Gatorade electrolytes to put back what you lose in sweat
  • Propel provides electrolytes and is an excellent source of vitamin B and antioxidant vitamins C and E

Water is good at dissolving. That works well when you mix up your  powdered sports drink. However, not when you want to remove harmful materials.

That’s where water filters come in. Water filters remove harmful contaminants through either physical (straining water through a fine sieve) or chemical filtration (passing water through an active material that removes impurities). With that in mind, there are a few basic types of water filters:


  • Micro Filters: The most common, micro filters work by passing water through a membrane fine enough that only clean water can come out. It leaves bacteria, parasites, dirt and contaminants behind.
  • Activated Carbon Filters: Used in treatment plants and household filters. These pass water through activated carbon granules, which attract and trap impurities through absorption.
  • Reverse Osmosis Filters: These filters are similar in that they employ a very fine membrane. But, they use osmotic pressure to force the water through, making it easier for the water to get through the filter while leaving contaminants behind.
  • Ion Exchange Filters: The simplest way to think of this filter is that it splits apart the atoms of contaminants to create ions. Then, traps these ions, releasing other, less harmful ions in their place. Many water filters utilize ion exchange to remove limescale. Also referred to as water softening.



Choosing the Best Water Filter


There are a lot of junk water filters on the market. To prepare for survival, you need something you can count on. The best water filter is long-lasting, durable, and effective. These are some of the best water filters for preppers, and they’re easy to find and buy online:


LifeStraw Personal Water Filter

LifeStraw Personal Water Filter for Hiking, Camping, Travel, and Emergency Preparedness, 1 Pack, Blue
105,918 Reviews
LifeStraw Personal Water Filter for Hiking, Camping, Travel, and Emergency Preparedness, 1 Pack, Blue
  • Removes Bacteria & Parasites: The Microfiltration Membrane Removes 99.999999% Of Waterborne Bacteria (Including E. Coli And Salmonella), And 99.999% Of Waterborne Parasites (Including Giardia And...
  • Removes Microplastics: Removes The Smallest Microplastics Found In The Environment (Down To 1 Micron), And Reduces Turbidity Down To 0.2 Microns
  • Rigorous Testing: All Claims Are Verified With Laboratories Using Standard Testing Protocols Set By The Us Epa, Nsf, Astm For Water Purifiers

This water filter has been on the market for years. It is one of the most popular out there, and for good reason. It’s lightweight and portable, making it easy to toss it in your  backpack or pocket when it’s time to go. More importantly, it’s effective.

This filter is effective down to 0.2 microns, small enough to remove 99.9999% of waterborne bacteria and 99.9% of protozoan parasites. It works like a straw, and turns any stream, pond or puddle into a viable water source.

Its only real downside is its limited functionality, in the sense that you have to dip it in water to drink. It doesn’t offer any way to store clean water. It’s great for when you’re on the move, but not so great for long-term survival on one location. It has a lifespan of 1,000 gallons (or 4,000 liters).


Sawyer Mini Filtration System

Sawyer Products SP128 Mini Water Filtration System, Single, Blue
  • Ideal for outdoor recreation, hiking, camping, scouting, domestic and International travel, and emergency preparedness
  • High-performance 0.1 Micron absolute inline filter fits in the palm of your hand and weighs just 2 ounces; 100% of MINI units individually tested three times to performance standards by Sawyer
  • Attaches to included drinking pouch, standard disposable water bottles, hydration packs, or use the straw to drink directly from your water source

Popular among backpackers for its light weight and compact size, this filter offers efficiency in a tiny package. The Sawyer Mini weighs just 2 ounces and fits in the palm of your hand.

Using a hollow fiber membrane inline filter, it filters out 99% of all impurities, from bacteria to protozoa, and can be attached to the drinking pouch. The pouch is handy because it slips easily into your pack, and is compatible with most water bottles. Additionally, you can stick it right into your water source and drink through it like a straw.

The Sawyer Mini is said to be effective for 100,000 gallons. A word of caution to drinkers: while the filter and pouch are well-made and durable, if you squeeze it too hard, you can damage the filter.


Katadyn Hiker Pro Transparent Water Filter

Katadyn Hiker Pro Transparent Water Filter, Lightweight, Compact Design for Personal or Small Group Camping, Backpacking or Emergency Preparedness, one Size (8019857)
  • Proven protection against bacteria and protozoan cysts down to 0.2 micron with pleated glass-fiber filter media
  • Activated carbon in the core of the filter improves the taste and reduces chemicals in your drinking water
  • The field cleanable filter protector screen extends the life of the cartridge in challenging conditions

One of the first things you’ll notice about this filter is how well-built it is. This thing is sturdy and dependable. It gives you the kind of confidence that comes from knowing your gear can be counted on.

A pump-style filter that comes with a durable canister,  it works by pumping water through an activated carbon core filter. The core is replaceable (a filter protector screen extends its lifespan and makes it easy to clean/replace) and it filters particles down to 0.2 microns.

The canister is handy, because you can see it filling with water as you pump. However, the filter component is compatible with other hydration bladders and wide-mouthed water bottles. Canister included, the Katadyn Hiker Pro weighs about 11 ounces.


MSR MiniWorks EX

MSR MiniWorks EX Backcountry Water Purifier System
  • Microfilter water filter pump and 50 purification tablets for hiking, backpacking, camping, travel, survival, and emergency preparedness
  • Replaceable carbon and ceramic filter removes bacteria, protozoa, organic compounds, and particulate; Aquatabs protect against viruses
  • Pumps at a rate of one liter per minute; compatible with a variety of wide mouth water bottles, and hydration bladders (sold separately)

The MSR is much like the Katadyn in that it’s also a pump filter, and uses a similar purification process. The MSR uses replaceable carbon and ceramic filters, each of which treats up to 2,000 liters of water. The filters eliminate 99.9% of bacteria, and 99.9% of protozoa.

At 1.3 pounds, the main drawback is its weight. Some ultralight preppers would balk at adding that much to their pack. Especially when so many lighter options are available.

The MSR has been on the market for years, and it’s still popular for good reason. It works well, and it’s durable. You can knock it around a bit and know that it’s still effective. It’s great for camping in the same area for a period of time, but still want to be ready to move when the time comes.


Big Berkey BK4X2 Countertop Water Filter System

Big Berkey BK4X2 Countertop Water Filter System with 2 Black Berkey Elements and 2 Fluoride Filters
1,940 Reviews
Big Berkey BK4X2 Countertop Water Filter System with 2 Black Berkey Elements and 2 Fluoride Filters
  • Includes Big Berkey stainless steel housing (Upper, Lower, Lid and spigot etc.), 2 Black Berkey Filters, and 2 Fluoride Elements.
  • Holds 2.25 gallons of purified water. Designed for home use for 4 to 16 people
  • The Big Berkey is made with High Grade 304 Stainless Steel and measures 8.5"D x 21"H when assembled

An ideal system for larger groups of people, this filter system is great for the long haul. It’s designed for long-term use by 4 to 16 people. It makes a great addition to your home, camper, campsite or shelter.

This filter uses gravity to drive water through its filter to the reservoir and spigot at the bottom. It holds 2.25 gallons of purified water. It’s made of stainless steel for durability, and designed to keep you hydrated through the end times.

The system includes two 3,000-gallon filter elements, for a lifespan of 6,000 gallons. Also, other filter elements are sold separately. You can stock up and get decades of use out of this system.



Filtration vs. Purification

Lastly, remember that water filtration and purification are not the same thing. And the difference is quite simple.

  • Water filters remove particles, thus making it safe to drink.
  • Water purifiers render harmful particles inert.

Both methods can be effective, and in a survival situation it’s best to be prepared for both. Water purification tablets such as chlorine or iodine tablets are a good backup for your water filter. UV purification and distillation are also good options. In addition, boiling is effective at killing harmful bacteria and viruses.