Emergency Water Purification Systems for Your Bug Out Bag

Depending on your weight you are going to need about half a gallon to a gallon of water per day.  And you still may need more depending on the amount of exertion and sweat you are putting out.

Because we normally just get our water from the tap it is really easy to forget how much water a person uses in a day until you have to carry that water for any length of time.  Then water becomes a huge time and energy consuming concern.

If you are on foot you won’t be able to carry much so it’s going to be critical that you purify and treat water that you can find.  Even if you are traveling in a vehicle you won’t want to waste gas hauling a bunch of water around when there are much lighter options for emergency water purification systems.

You Are Going to Need Two Types of Water Treatment to Purify Your Water

  1. Some form of Filtration
  2. Some Form of Antiseptic to kill germs, bacteria and other pathogens.

Water Purification Tablets (or Drops)

For emergencies, the first thing that needs to be in every bug out bag is water purification tablets and drops.  The same is true for camping.  No natural water source should ever be trusted anymore.  Sure there may be some “pristine” water that you find, maybe a spring, but it’s not worth taking the chance of getting sick especially if it’s an emergency and you cannot get to a hospital quickly.

There are a wide variety of tablets available and any will do, so get a couple of different kinds if you want and be redundant about it.  They don’t take up much room or space and don’t cost much, so get enough that if you lose a few or a pack no big deal.

Aquatabs by MSR are not the cheapest you can get.  I think Colman has a bottle you can get for a dollar less for 50 pills.  But MSR is a reputable higher end company and I don’t think there is much difference in the effectiveness of any of the different brands.  They all have harsh chemicals that will kill bacteria, viruses, and parasites.  The thing I like about the Aquatabs is that they come in separate foil packs that are not going to weigh as much as a glass bottle.  But this is just an example of what I have used and like I said, get a bunch and try a few different kinds.  Also, make sure to follow instructions and let the water off gas sufficiently before consuming.

Product: MSR Aquatabs

Price: $9.95 for 30 which will treat up to 60 liters of water

Best Place to Buy:  Moosejaw.com

Emergency Water Purification Systems for Your Bug Out Bag
chemical water purification tablets

If you aren’t picky about things floating around in your water, having enough purification tablets alone will ensure that you at least survive any bacteria or viruses that might be in the water.


I typically say that “all water purification chemicals” are basically poison and that is how they work to kill nasty pathogens and because of that they are all the same.  But that isn’t necessarily true.  Something that I have become aware of recently is that a supplement that I use called Nascent Iodine can be used to purify water.  It can be used just as effectively for swimming pools, for example, as Chlorine but for some reason, it isn’t.  I must say I haven’t tried it yet but I will.  I have been a little reluctant to try it because I have this crazy bias in my head that for something to work to purify water it has to be toxic or specifically labeled “for water purification”.  But if it is good for you and you take it every day as I do as a supplement, you might think “it can’t be any good for killing terrible nasties in the water”. 15 drops per liter of Nascent Iodine per liter or quart.  Let stand for 30 minutes to an hour depending on cloudiness.  If you are like me though and feel more secure with something specifically labeled for “Water Purification” I have seen a couple of Iodine based products:

Emergency Water Purification Systems for Your Bug Out Bag
Chlorine Tablets

Product: Potable Aqua Water Tablets

Price: $8.99

Cheapest Place to Buy: Amazon

Weight: 1.4 Oz



*Nnote of caution that should be made with iodine is that it won’t kill cryptosporidium and that means it should be used with a really good crypto capable filter.

UV Pens

The same is true for UV treatment.  These portable little devices are like little flashlights that will kill any living organisms in the water when you stir the water with them.  I like these because they don’t mean adding chemicals like chlorine to the water but I don’t like them because they depend on batteries.  Batteries are heavy and they are not convenient to get even when the stores are open, let alone in a Zombie apocalypse.  In addition, they can be awkward to use and especially on larger quantities of water, pretty much impossible.  Pricey too but if you like the idea of no chemicals…

Water Filtration

Water filtration will get most of the particles and chemicals out of the water and clear up its appearance a lot if has started out looking dirty.  Some will filter down as small as a virus.  The key to shopping around for a good filter is to find the one that filters the smallest particle.  When coupled with purification tabs, you can ensure that your water is safe with a good filter system

Know How to Make your Own Filter

There are a lot of portable water filters on the market today, but being aware of how to make your own charcoal and then make your own charcoal/sediment filter is a good idea even if you have an awesome ‘store bought’ one.  Charcoal is a fairly involved process yet easy enough to make over an open fire.  But I approach it like fire making itself.  I like knowing how to make a fire by rubbing sticks together but I’m going to do all I can to ensure I have matches, flint and other methods of fire starting in my pack so I don’t have to.  I know how to make a half decent sediment and charcoal filter from scratch in the woods but I’m going to do everything I can to carry a well-made filter (or 2 ) in my pack to accompany my purification tablets.

*Note You may be able to do without a filter but you won’t be able to do without purification tablets or boiling your water which is time-consuming and takes a lot of fuel.  In an emergency always to use tablets or other forms of water treatment to kill pathogens.  In a pinch, a few drops of bleach will do too.

The Lightest Water Filters On The Market

I started carrying a water filter on the Thompson River as it is a very dry arid place (aside from the river that is), many years ago with an MSR ceramic filter.  It was one of the early models of camping/hiking filter systems.  I don’t think the design has changed much but I did find the pump was a pain and of course the ceramic filter was as heavy as lead.  But it was lighter than the gallons of water I had to pack into that particular location so I appreciated it.  There were other problems like the fact you had to pump water through it and it took quite a lot of pressure to do it.  It was a reusable filter so that was one good thing.  Overall though it was a pain to use.

Today there are much lighter options.  Lifestraws are very popular and were the first but Sawyer filters are smaller based on a similar concept.  Sawyer filters also have a lot of nifty attachments.

Emergency Water Purification Systems for Your Bug Out Bag
Life Straw filter: created for use in developing nations has saved many lives

Product: LifeStraw

Price: $17.67

Cheapest Place to Buy:  Amazon.com

Weight: 2.0 oz

The idea with these microfilters is if you are walking along and come across a body of water you would like to drink from you can just dip the Lifestraw into the water like a straw and drink right through it.  They claim it will purify bacteria and other pathogens.  Call me old-fashioned but I still feel more comfortable throwing some chlorine or iodine in the water then filtering it but, if you are thirsty and you need it right away, having a drink from the filter alone should be ok.  It has saved many lives in impoverished countries so there is something to be said for it.


The thing I like about the Sawyer system is they made the filter so it could be screwed onto a regular plastic water or even pop bottle.  So if your Dasani runs out you can fill it right back up.  Since then they have made a bunch of other attachments that look pretty good like the bag system that should save a lot of weight in containers.

Emergency Water Purification Systems for Your Bug Out Bag
Sawyer Filter: Is the lightest and most compact option for any emergency, backpacking or camping filtration system

Product: Sawyer Mini Water Filtration System

Price: $19.97

Cheapest Place to Buy:  Amazon.com

Weight: 2-5 oz with attachments


Of course, having said all of that I do have to insert the water purification system I picked and that is the Platypus Gravityworks 4.0L Filter System.  I like the idea of the small filters and I have one myself and the Gravityworks has about the same sized filter, however, it’s the ultralight water containers that it comes with it that really make this system shine.  Sure it’s a nice idea to be able to dip a straw in the water and fill your hiking bottle, but if you are going to set up camp for the night and want to have some to boil and cook with….If you want to have a relaxing time instead of constantly filling up little bottles or going to the pond to drink directly from it, then the 4-liter bag system is easy and gets you a good amount of water in one go.  Enough to have a drink, brush your teeth with, have a cup of tea and cook your instant noodles in…for two.  And while it is pricey, for what it does, its the lightest and most convenient thing going.

Emergency Water Purification Systems for Your Bug Out Bag
Platypus filter system is my first choice in Packable water filtration

Product: Platypus Gravityworks 4.0L Filter System

Price: $119.95

Cheapest Place to Buy: Moosjaw.com

Weight: 10.75 oz

There are also smaller/lighter Platypus systems if you don’t mind refilling more than once a day.  Like the 2.0L System and the 2.0L Water Bottle Filter System.   Very nice and very packable.

The Platypus System is what I use when camping and would rely on it in an emergency.

  • It is simple.
  • It is ultra light (though not as light as the slightly less convenient mini filters)
  • It has large (4 Liter/ 1Gallon) containers.  Fewer trips to the water source!
  • Gravity powered.  No tedious pumping.

Of course my preferred method of water purification in an emergency is to distill the water, however, I have yet to see a distiller that will fit in a bug out bag.  There are some off-grid distillers that come close but I’m still waiting for someone to make one small and light enough to fit in a backpack.

For a more indepth discussion on Water and the distillation process see my article here

4 thoughts on “Emergency Water Purification Systems for Your Bug Out Bag”

  1. I love hiking and camping and know how important water is. I once drank untreated water and it made me really sick. Since then I always carry purification tablets.

    I absolutely love your review regarding water treatment and purification and find the information very helpful.

    I agree, by boiling the water can be very effective, but it is very time consuming and a waste of energy.

    Do you know about any household items or any other cheap alternatives you can use to filter water?

    I always use the tablets and do not want to spend too much money on filters.

    1. I have to confess I have used tablets and then coffee filters but I wouldn’t recommend it lol.  Those only get out the big stuff.  I did mention but did not get into how to make a filter in the woods.  If you know how to make charcoal which is just anything carbon based like wood then burn or ‘char’ it in an almost air tight container so it never creates a flame like a tin can with a lid, then you can break it up and put that into a coffee filter and then string another coffee filter filled with sand above the charcoal.  putting them into the tops of cut off pop bottles will help keep them steady enough then pour water on the sand then let it drip down through the charcoal and into another container……  This is a very primitive method for emergencies and cheap!  But as I mentioned, I have had ’emergencies’ even while camping haha.  The Sawyer and the lifestraw are the cheapest and lightest I know of that are well known, popular and so tried and true.  I’m sure there are slightly cheaper knock offs but you will only be saving 3 or 4 bucks.  Thanks for commenting.  Have fun camping and let me know if you find a good filter that costs less and I’ll do a review:)

  2. Great info. We’ve seen some eco-conscious travellers use water purifying tablets to reduce the number of plastic bottles they use on their travels in Thailand. These people are fantastic but, sadly, not enough people do this and most choose the easy option of buying a plastic bottle of drinking water. I suppose it’s understandable when you’re on holiday and just want to relax and have fun, but it does have a really negative impact on the environment, as a huge number of plastic bottles are used just once and then thrown away. Koh Lanta tries to encourage people to use refillable water bottles and they don’t even need to purify the drinking water any more, as we recently started an initiative where local businesses give out free drinking water to people with a refillable water bottle. It’s great to find out about the different water purification options people could use if they don’t have drinking water easily available. Thanks for sharing the thorough info 🙂

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