Water Treatments for Backpacking and Hiking

Water is plentiful on the trail from springs, streams, rivers, and ponds… but not every clear water source should be trusted. Some hikers have survived without treating water, but that doesn’t mean dangerous impurities do not exist in these sources.

Water treatment methods have evolved past the days of iodine tablets (but that doesn’t discount iodine as a treatment!). Filters are more efficient and lightweight than ever before, and purifying droplets have proved worthy with barely altered taste, if any at all.

When looking to treat water, these impurities pose the most risk:


-Campylobacter, Salmonella, Shigella, E. coli

-Enterovirus, Hepatitis A, norovirus, rotavirus

Below are the best ways to treat your water while hiking or backpacking. These items are chosen because of popularity, weight, and effectiveness. Filters only purify the water from Protozoa & Bacteria. When looking for a filter, anything less than one micron will be effective for purifying. Purifying and treating your water is a personal choice. I would recommend only skimping if your source is a pristine mountain spring. Giardia is real and has been contracted from sources on the trail. Choose wisely or play it safe and always treat your water.

1. Boiling Water

If you find yourself with a frozen filter or lacking drops, you can always boil your water (rolling boil for one minute). I do not recommend doing this for your entire hike. This wastes fuel and time, but will work just fine in those sticky situations.

Situated at an elevation of 6,500 feet or higher? Boil for three minutes instead of one minute.

Protects from: Protozoa, Bacteria, & Viruses (very effective)

2. Aqua Mira 


Aqua Mira is one of the most popular ways to purify water on the trail. Aquamira is lightweight chlorine dioxide (not Iodine or chlorine) but not readily available in every town. I recommend purchasing Aquamira off Amazon for cheap deals, then shipping it in a mail drop.

Personal Note: I used Aquamira for the southern states of my trip. I loved Aquamira and had no problems. I only switched because I hiked with my boyfriend and it was more cost efficient for us to just buy a filter.

Purifying Agent: Chlorine Dioxide
Price: $15 for 1 oz Part A and 1 oz Part B (might pay more in an outfitter)
Protects from: 99.9% of bacteria, viruses, and cysts including Cryptosporidium and Giardia
Weight: 2 oz if using the 1 oz Part A & 1 oz Part B
How To: Mix 7 drops of Part A & 7 drops of Part B for 1 liter of water
Wait Time: Wait five minutes for Part A & Part B to mix, then pour in your water, and wait 15 minutes (30 minutes for cold water) to drink
Taste: Only if overdose the solution/water ratio
Website: www.aquamira.com

3. Household (laundry) Bleach


I hiked the trail in 2013. I never saw anyone use bleach for purification. However, while meeting some 2012 thru-hikers, they seemed surprised no one used bleach. Just goes to show how trends can change even within a year.

Remember: Choose unscented bleach with the fewest additives.

Purifying Agent: Sodium Hypochlorite (source of chlorine in bleach, 6%)
Price: $5-$10 for a gallon
Protects from: Giardia, bacteria, & viruses
Not effective in protecting from: Cryptosporidium
Weight: Depends on how much you choose to carry in a dropper
How To: 2-4 drops per liter
Wait: 30 minutes
Taste: Some people experience a taste while others don’t. Some claim the smell is more prominent.

4. Potable Aqua Iodine


Iodine is one of the most recognizable ways to purify water. Iodine does leave an unpleasant taste in your drinking water, but the taste can be neutralized by taste-neutralizing tablets.

Purifying Agent: Titratable iodine
Price: $7-$11
Protects from: Giardia, bacteria, & viruses
Not effective against: Cryptosporidium
Weight: 6 oz
How To: 2 tablets per liter
Wait: 30 minutes
Taste: The taste is apparent unless you buy the taste-neutralizing tablets.

5. Katadyn MicroPur Tablets


Each tablet is individually wrapped.

Purifying Agent: Chlorine dioxide
Price: $13 for a packet of 30
Protects from: Protozoa, bacteria, & viruses
Weight: 0.9 oz
How To: 1 tablet per quart
15 min to destroys viruses and bacteria in 15 min
30 min to destroy Giardia
4 hours to destroy Cryptosporidium

6. MSR Sweetwater Droplets & MSR Sweetwater Filter

msr_sweetsystemfix                                    rebofix

The MSR Sweetwater droplets are meant to be paired with the MSR Sweetwater Filter as a filtration system. I knew hikers to use simply the droplets. However, the droplets are only effective for viruses, not bacteria or protozoa. The filter is effective for bacteria and protozoa, not viruses. See how these two are paired together now?

Purifying Agent (in droplets): Sodium Hypochlorite (3.5%)*
Price: $100 for the entire system ($10-$15 for just the droplets)
Protects from: Bacteria, protozoa, & viruses
Filter: Carbon Silica, .2 micron
Filter Efficiency: 1.25L per minute
Weight: 14 oz
Note: Filter is freeze-proof

*This is the same active ingredient as bleach has but a lower percentage. The MSR Sweetwater droplets are made for human consumption, unlike bleach.

7. Sawyer Filtration Products

Sawyer filters are extremely popular filter systems for thru-hikers. My boyfriend and I used the Sawyer Squeeze for the second half of our thru-hike.  These filter systems might be difficult to collect water from shallow sources. I would recommend carrying a Gatorade bottle, which is better for ‘scooping’ water than the Sawyer or Platypus bags. The cartridge life for Sawyer Squeezes boast 1 million gallons. The Sawyer Squeeze can act as a gravity filtration system but do not expect quick results.

Personal Note: The bags Sawyer provides for their squeeze products are not necessarily reliable for long term, everyday use. We ended up using our Platypus bags. Luckily, Platypus bags are compatible with the filter’s threads. On a side note, squeezing gets old after a while (as I am sure pumping does for other filters) especially when the filter starts to clog. Do not necessarily rely on the syringe to completely fix all clogging.

Sawyer offers a variety of systems. All Sawyer products below have these specifications:
Filter: Hollow fiber membrane, 0.1 microns
Protects from: Protozoa & Bacteria (not viruses)
Filter Efficiency: 1.7L per minute

Sawyer Squeeze Mini Water Filter 


Price: $25
Weight: 2 oz
I would not recommend this filter for a couple, perfect for a solo hiker though.

Sawyer Squeeze Water Filter


Price: $40
Weight: 3 oz

Sawyer Complete Water Filter System (not squeeze)


Price: $110
Weight: 16 oz

Sawyer 3-way Inline


Price: $60
Weight: 2 oz

8. Platypus Gravity Works Water Filtration System


Price: $110
Filter: Hollow fiber membrane, 0.2 microns
Protects from: Protozoa & Bacteria
Filter Efficiency: 1.5L per minute
Weight: 11.5 oz

9. SteriPen


I did not see many thru-hikers using the SteriPen on the trail. I think the SteriPen is more effective for short trips because the system does require batteries. The SteriPen is also only effective with low turbidity (cloudiness) in the water. SteriPen can also double as a flashlight.

Price: $90-$150
Method: UV Lamp, lamp life for 8,000 treatments
Protects from: Protozoa, bacteria, & viruses
Efficiency: 32 oz per 90 seconds
Battery Life: 100 treatments
Weight: 11.5 oz

10. Katadyn Hiker & Hiker Pro Filter


This is the Hiker Pro.

The difference between the Hiker & the Hiker Pro is the quick release hoses and the field cleaning kit in the Hiker Pro.


Price: $70
Filter: Carbon core, 0.3 microns
Protects from: Protozoa & Bacteria
Filter Efficiency: 48 strokes per minute provides 1 liter
Weight: 11 oz

Hiker Pro

Price: $85
Filter: Carbon core, 0.3 microns
Protects from: Protozoa & Bacteria
Filter Efficiency: 48 strokes per minute provides 1 liter
Weight: 11 oz

Natural Option: Grapefruit Seed Extract


I have never seen this used on the trail. I just love the idea of a natural purifier for those hikers in which do not want to drink chemicals and don’t have the budget for a filter. Apparently, GSE is very acidic and leaves a bitter taste. GSE has been used by practitioners to treat microbial, protozoan, fungal, and viral infections. The web has many accounts of GSE water purification in the backcountry but not for an extended period of time or in exceptionally impure water.

Price: $12 per 1 oz bottle
Protects from: Protozoa, bacteria, & virus
Weight: 1-2 oz
How To: 6-10 drops per liter
Wait: 30 minutes
Taste: Bitter

Purifying water on the trail should not be taken lightly. Sickness from impure water can ruin your hike. I only have experience with two of these methods (Sawyer Squeeze and Aquamira) listed above, but that doesn’t mean one method is better than the other.

The purification processes listed above are not the only options for back country water treatments. If you are interested in more options, check out THIS link for a comparison review of the most popular systems available (including some on this list).


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Comments 7

  • William : Aug 28th

    I am planning a 4-day canoe trip this fall.

    Recently I was researching portable water filters and bought a LifeStraw. Have you any experience with it?

    I read this review and decided to buy it, but haven’t tried yet: https://campingandcamping.com/8-best-backpacking-water-filter-reviews-tips/

    • Bluntley : Dec 31st

      I consider those more of an emergency thing. I mean i guess for just 4 days its fine but its annoying to try and pull water through stuff .

    • Jerry : Feb 22nd

      Lifestraw has a water bottle.. put water in the bottle and suck it up thru lid

  • Mickey Bruce : Aug 5th

    What are your thoughts on using the platapus as a water collector for sawyer filter? Do you use bigzip or hossier? Thank you for all your great info.

  • Steve O : Nov 2nd

    I am really redundant. I have a Katydyn Vario, Sawyer squeeze and Polar Pure. Also a small eye drop bottle of chlorine

  • Jerry : Feb 22nd

    I’m 71.. in the old days we used 3 drops chlorine bleach with a tampon in the bottle… pull the string and snuggle the tampon in the neck.. great filter


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