Questions tagged [water-purification]

Questions about making the water found outdoors safe for drinking.

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58
votes
10answers
13k views

What is the safest way to purify water?

There are a number of ways to purify water, off the top of my head we have filters, iodine, and boiling. Clearly each has some advantage/disadvantage (iodine tastes terrible, boiling takes time). ...
56
votes
4answers
186k views

How long does water need to be boiled for to kill all bacteria / viruses?

This has come up a few times in a few other questions, but I've heard varying opinions from different people in a number of answers and comments on here - some saying that just boiling for a moment is ...
53
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4answers
33k views

Is drinking urine safe?

We've all heard stories about how people saved their lives by drinking their urine. Is drinking urine safe when there are no other water sources available? Can I filter it with a water purifier?
37
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4answers
13k views

Ways to desalinate water when “lost at sea”?

In recent news reports that all seem to be saying the same things: Jakarta Post Indonesian teenager survives 49 days adrift in Guam waters NPR: 19-Year-Old Survives 49 Days At Sea After Floating Hut ...
35
votes
1answer
38k views

How much sea water can I safely drink?

Anyone who has played in the ocean knows getting a little sea water in your mouth and swallowing it will not kill you. Seawater contains salt. When humans drink seawater, their cells are thus ...
31
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4answers
40k views

What are the different methods to purify water?

What methods can I use to purify water? And what's the difference between those several methods (safety, duration needed, ...)?
31
votes
7answers
10k views

Where in the Alps is it safe to drink the water without filtering?

In some places, the Swedish Lappland for example, it's perfectly fine and even recommended to drink water directly from streams. Is it also recommended whilst hiking in the Alps, and if so is it only ...
29
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6answers
13k views

Do you need to purify all mountain water sources

I was just reading this question What is the safest way to purify water? Now I walk a lot in Snowdonia in North Wales and on occasion I drink from mountain streams. I've even camped next to mountain ...
29
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4answers
20k views

Do iodine water treatment tablets have negative effects?

I've heard that iodine water treatment tablets can have negative side effects. Is this true? If so, what are some healthier alternatives?
26
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4answers
3k views

Why are people so worried about Giardia?

Everyone I have ever been camping with seems to have an unwritten rule never to drink from streams no matter how clear they might seem, for fear of Giardia. I have also heard people telling about ...
26
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2answers
5k views

In a survival situation, should I drink unpurified water?

If I am in a survival situation, is there any reason I shouldn't drink the available water? I am aware of Giardia and cholera. Are these worthy concerns, or are there good enough cures available that ...
25
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5answers
28k views

Can any waterborne pathogens survive boiling?

I know that boiling does little to break down chemical contaminants or heavy metals. But I'm unsure if it kills all microbial life. Are there any waterborne illness-causing viruses/bacteria/protozoa/...
22
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3answers
9k views

Can you boil/decontaminate water with heat from a magnifying glass?

A bit hypothetical, but ruling out being able to use a solar still, or the SODIS method, could you make water drinkable by using the suns heat through a magnifying glass? Paper self ignites at 451° F ...
20
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3answers
4k views

Does a life-straw replace my water while hiking?

Let's assume I hike in a region with a lot of streams, rivers and lakes (South-Germany etc.) not longer than for two days. Am I supposed to use a life-straw as my primary water-source or should it be ...
16
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3answers
5k views

Is drinking water containing dirt harmful?

I noticed that if I collect water from a stream dense of small debris/thin mud, if I keep the water bottle close to the surface, while it takes a longer time to fill the bottle, the water is cleaner ...
16
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3answers
27k views

Water filters - why sand and rocks?

Saw a video on youtube where some guy made a water filter out of a bottle, charcoal, sand and little rocks. He commented that since the charcoal is very porous it's great for filtering. Then, after ...
15
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3answers
7k views

Where can I find an iodine crystal water purification product?

For years I used a product called Polar Pure for water purification when weekend backpacking. It was an iodine based solution, so not great for a thru-hike, but fine for a week or less. Specifically, ...
15
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1answer
2k views

Will Iodine Tablets Ruin My CamelBak?

In the past, I have gone backpacking with some fairly expensive, heavy water purification tools. But the more I read about water safety in California's Sierras (here and here), the less I think these ...
14
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5answers
1k views

Filtering fine silt/mud from water (not necessarily bacteria etc.)

We are heading for a trek in the Fann mountains and I've heard a lot of the water there is cloudy with very fine silt particles in it. I noticed most water filter manuals explicitly tell you not to ...
14
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2answers
7k views

How do I desalinate seawater?

I know I shouldn't drink seawater (because of the salt it contains), but how can I desalinate it?
14
votes
1answer
2k views

How do I test my water filter?

How can you verify that a water filter still works? I've had one for several years and I suspect it may not be working. Is there a way to test and make sure that it still filters to the factory ...
14
votes
1answer
5k views

Safe to use Old Water Filter?

I have a PUR Hiker Microfilter and a Katadyn Water Microfilter sitting in my closet that I only use once in a great while (I don't go on overnight backpacking trips very often). Whenever I do plan on ...
13
votes
2answers
1k views

What backwoods trick to get pure water produces the most safe water?

So I read this answer and I was wondering what contraption produce the most water when you don't have a water source? So what water trap produces the most water? Specifically, what should I do with my ...
13
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2answers
5k views

How do you boil water without a proper container?

Suppose you don't have a pot or any other fire proof container to boil water in, but you need to boil it for safe drinking water. How else can you boil the water?
12
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2answers
7k views

Will boiling be enough to decontaminate standing water from pathogens and toxins?

Will the boiling of the water itself be enough to decontaminate water taken from such standing water reservoir as that: This water looks horrible, and probably drinking it raw would cause serial ...
12
votes
4answers
1k views

How can I desalinate ocean water enough for cleaning or showering?

I'm planning for a long cruise in my small yacht. The water tank in the yacht has enough clean water to drink, but not quite enough for showers, cleaning the dishes etc.. Desalinating ocean water ...
12
votes
4answers
273 views

Will any filter/pump purifier last through longer hikes?

I've been reading a lot of product reviews, and filter/pump solutions seem to be very high maintenance, very heavy, or both. Are there any lightweight filters which can be relied on for many liters ...
12
votes
1answer
406 views

How to tell if water is likely to have cryptosporidium?

I often use CLO2 (for example this product) to treat drinking water when I’m backpacking and boiling is not convenient. The instructions for the product say that the dose should be tripled if the ...
11
votes
3answers
1k views

How do you make an emergency water filter and purifier?

How do you make an effective water filter using the natural elements of the great outdoors? Suppose your only source of water was dirty and questionable at best. How could you make it potable without ...
11
votes
5answers
20k views

Is pouring boiling water into a plastic Nalgene bad for you?

I've heard that pouring boiling water into a Nalgene-style bottle is either completely fine or definitely going to kill you. Which is it? Are there any scientific studies demonstrating exactly what ...
11
votes
2answers
17k views

Is it safe to use water purification tablets after their expiration date?

As I understand it, water purification tablets (Chlorine, in this case) are just chemical tablets sealed in foil. So what causes them to expire? Are they still safe to use after their expiration date? ...
10
votes
4answers
9k views

Are water purification tablets safe?

There are a few questions regarding safety of water purification, one regarding expiration date, another regarding iodine, but I know that there are more than one types of water purficiation tablets. ...
10
votes
1answer
1k views

Iodine tablet correct use and efficiency

I've used these many times before, always followed the instructions (3 tablets/Liter, shake, wait 30 minutes minimum) and never had (or noticed) any issues. I've always been under the impression, ...
10
votes
3answers
1k views

Can any automotive fluids be made safe to drink?

My vehicle has broken down in the middle of a desert, I have some tools but I am out of water. I have the ability to make a fire. I know that drinking antifreeze is fatal, but I am wondering if I ...
10
votes
1answer
2k views

How do slow sand filters work and are there any alternatives?

Slight Introduction: A slow sand filter is a filter used to purify water. The original design is composed of a layer of gravel, then a layer of fine sand. Sometimes, however, there is an extra layer ...
9
votes
2answers
1k views

Is it safe to put snow in water filtration?

I was wondering if it is safe to put snow in water filtration and then just wait until it melts down if the temperature is right. Of course, carefully picked, clean looking snow.
9
votes
1answer
2k views

Does water in the sun get purified from or polluted by algae, fungi and bacteria?

We live at 27° latitude, about 200 metres above sea level and drink water from PET bottles laying around on the soil (SODIS method). They are filled with fresh water from a well and reused over and ...
9
votes
2answers
183 views

Are there any contaminates that become more toxic when boiled?

The answers at How long does water need to be boiled for to kill all bacteria / viruses? indicates that boiling water kills bacteria & viruses. But boiling does not remove any chemical ...
8
votes
2answers
2k views

Drinking water in Dartmoor

Is it safe to drink water from streams in Dartmoor using simple purification methods? I'm planning a trip and am looking to filter using a Millbank bag and then boil for four minutes to kill off any ...
8
votes
3answers
2k views

What water is fit for cleaning hands & gear during a visit to the Great Outdoors?

I am looking to setup dish and hand washing stations for a group of folks in a fairly-wild woodland, in a car-camping summertime setting, for 2-5 days (depending on the occasion). Is stream water fit ...
8
votes
1answer
291 views

How can I tell when water is contaminated with industrial chemicals without any special equipment?

With fracking, chemical spills, and all sorts of environmental nonsense on the rise, water quality can be compromised in some areas. How can I tell when it's not safe to consume even after filtering ...
8
votes
2answers
248 views

What backpacking water purification techniques can be substituted safely during a city's boil order?

Can I use my Sawyer filter when the city issues a boil order? Or could there contaminants such as viruses present that require boiling? How about other filters such as carbon filters? I'm confident ...
8
votes
1answer
3k views

What micron level is needed to properly filter viruses from water?

While viruses are not commonly encountered in the great outdoors there is no doubt that many areas of the world that we travel, or live within, that are contaminated with viruses (hepatitis A, ...
7
votes
3answers
314 views

When to perform a filtering of the water?

Let's imagine I'm hiking and I find a water source - like a lake, a stream or a well, and I want to fill my water bottle with it. I have a bottle and a water filter. And a bandana. Since I can't ...
7
votes
2answers
460 views

Water filters: is there always a tradeoff between longevity and safety

My research thus far has acquainted me with a kind of trade-off: one can try to minimize the amount of contamination (from bacteria/parasites) or one can try to minimize the amount of particulates ...
7
votes
1answer
188 views

How long is an activated charcoal filter good for after initial use?

I have a water filtration system that uses activated coconut shell carbon as its media. The filter is listed as being able to purify up to 50 gallons, but I won't be using it for anywhere near that ...
6
votes
3answers
6k views

Why is boiling water making my steel pot brown?

Lately, as I boil water in a steel pot, it is making the pots very dark brown, and the inner surface of the pots seems to have changed to feeling rough and scrubby. Can anyone help with this? Also,...
6
votes
2answers
37k views

What is the minimum amount of water per day to survive?

I am disabled in the wildness, there are no natural water sources available. I have 2 gallons (7.5 liters) of water. The only practical solution is to sit and wait for rescue. I will be resting in ...
6
votes
1answer
648 views

What are the most likely causes of unfilterable water contamination in upland UK areas?

I have a new water filter, which removes bacteria and protozoa. It's tempting to imagine that I can now go around drinking from whatever revolting-looking puddles I come across, but I'm mindful that ...
6
votes
1answer
183 views

Could a steam juicer be used to desalinate water?

Could someone use a steam juicer to desalinate water? The juicer is used on a stovetop and the steam rises to the fruit in the top basket and the juice collects in the middle pot. I think it might ...