# Boiling vs. Chemicals



## RossA (Oct 9, 2008)

I have been reading and learning a lot from others on this and other boards. I have a question about water purification.
I understand the purpose of chlorine (bleach) in killing impurities in water before drinking. I also now understand that household bleach (Clorox type) has a limited shelf like, but calcium hypochlorite (pool shock) has a very long shelf life, at least while it is dry before it gets mixed with water.
Accordingly, I have purchased the pool shock and am storing it in a dry place in case it's needed later.
However, I also see that some people say that you ALWAYS need to boil suspect water, even if you use chemical purifiers. That is what I don't understand.
Why boil if you have used chemicals properly, and why use chemicals if you boil?
City water supplies don't get boiled, they just get chlorine and maybe filtration.
I want to do whatever is best, but I don't understand if both boiling and chemical treatment are really necessary, and if so, why.
I am also posting this question on other boards to hopefully get a bunch of answers from people who know more than I do on the subject.
Thanks in advance.


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## LincTex (Apr 1, 2011)

If you have ever boiled a gallon of water over an open fire you will know how futile of an exercise that is. 

It takes a long time...... and a LOT of gathered wood!!

I see no need to boil if you have good chemicals.

Also, make several batches. You can pour water back and forth between clean buckets to get most all of the chlorine out once it has did its job!


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## RossA (Oct 9, 2008)

That's what I was figuring, but I wanted to hear it from others.


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## cantinawest (Nov 9, 2011)

LincTex said:


> If you have ever boiled a gallon of water over an open fire you will know how futile of an exercise that is.
> 
> It takes a long time...... and a LOT of gathered wood!!


That is why we love using solar cookers to boil water.
You can boil a lot of water on a good sunny day to store for days when you are not able to use the sun.
No cost, no expendable fuel needed.

We take our solar cookers camping and after cooking meals we put them to use boiling water for washing, drinking, cleaning etc.

...this parabolic is a bit large for most people, but it is very fast.
We use more traditional sized solar cookers.


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## camo2460 (Feb 10, 2013)

LincTex is right if you use chemicals there is no need to boil, just filter and treat. Conversely, if you boil there is really no need to treat with chemicals, just filter and boil. Boiling water on a small scale is fine if you have no chemicals, however in the case of large amounts of water, chemicals are the way to go.


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## RossA (Oct 9, 2008)

Very interesting about the solar cookers, but the question still remains, if you use chlorine do you still have to boil, and vice versa?


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## RossA (Oct 9, 2008)

Sounds like what I wanted to know. Using chemicals would be a heck of a lot easier.


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## TheLazyL (Jun 5, 2012)

If I was on the move - chemicals.

If I was staying put for a while and a camp fire wouldn't be OPSEC problem (save chemicals for later) - boil.

Or use a clear 2 litter plastic (PET) bottle and the sun's UV...



> Did you know that solar radiation from the sun can purify (disinfect) water and make it safe for drinking from harmful bacteria?
> 
> While so often we hear or read about the bad things that the sun is capable of doing to us, we should also know that some of the same energy from the sun can be harnessed for doing good. A few good examples include solar electric panels, solar hot water panels, and solar ovens.
> 
> ...


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## RossA (Oct 9, 2008)

This is a silly question , but since you specified a clear _plastic_ bottle, I assume that a clear glass bottle would work just as well?


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## TheLazyL (Jun 5, 2012)

RossA said:


> This is a silly question , but since you specified a clear _plastic_ bottle, I assume that a clear glass bottle would work just as well?


Nope. Must be clear plastic (PET).



> The recommended bottle to use is a "PET" bottle. It is very common and is typically used for soda or other soft drinks.
> 
> PET, PolyEthylene Terephthalate, Recycle code #1 on bottom of bottle.
> 
> ...


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## Caribou (Aug 18, 2012)

There are multiple ways to purify water. If you use chlorine you will probably want to get rid of the chlorine before you drink it. You can pour it back and fourth to aerate it, you can boil it, or you can just let it sit in an open container for a longer period. The advantage to boiling after treating is in the dispersal of chlorine.

The SOLIS method of purification works by using the UV rays in the sun to kill anything growing in the water. The containers need to be smaller as the sun will only penetrate so far into the water. Glass blocks UV rays so it is useless for purification.

You can also use reverse osmosis to filter your drinking water. I have even filtered the salt out of the ocean for potable water. There are books on each of these subjects so don't expect to learn it all from a few short posts. These posts should give you a base to start your studies.


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## cowboyhermit (Nov 10, 2012)

There are a few things that chlorine will not kill easily. A good example is cryptosporidium (one of the most common waterborne illness globally), it requires a combination of high concentrations of chlorine and time to be reasonably effective. It is possible to treat to high enough concentrations and then remove much of the chlorine as mentioned by others although this does make the process a bit less quick and easy. It is often easier and/or safer to add another means of treatment such as filtration, uv, or boiling and that is what water treatment plants (and pools) do to address chlorine resistant bugs like this one. Of course if you are dealing with clean, cold, clear water the chances of it being contaminated are less and for a healthy person something like crypto is just the runs although if you are less lucky


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## LincTex (Apr 1, 2011)

http://en.wikipedia.org/wiki/Cryptosporidiosis

Many treatment plants that take raw water from rivers, lakes, and reservoirs for public drinking water production use conventional filtration technologies.

This involves a series of processes, including coagulation, flocculation, sedimentation, and filtration. Direct filtration, which is typically used to treat water with low particulate levels, includes coagulation and filtration, but not sedimentation. Other common filtration processes, including slow sand filters, diatomaceous earth filters and membranes will remove 99% of Cryptosporidium. Membranes and bag and cartridge filters remove Cryptosporidium product-specifically.

While Cryptosporidium is highly resistant to chlorine disinfection, with high enough concentrations and contact time, Cryptosporidium will be inactivated by chlorine dioxide and ozone treatment. The required levels of chlorine generally preclude the use of chlorine disinfection as a reliable method to control Cryptosporidium in drinking water. Ultraviolet light treatment at relatively low doses will inactivate Cryptosporidium. Water Research Foundation-funded research originally discovered UV's efficacy in inactivating Cryptosporidium.


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## Caribou (Aug 18, 2012)

Every chemical requires a certain amount of contact time, some longer and some shorter. UV requires a certain amount of contact time. Some filters require a certain slow rate of flow. Boiling is not an instant fix. Whatever process you decide on will take a period of time to accomplish.


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## cowboyhermit (Nov 10, 2012)

Thanks LincTex, that's good info, shows what I was trying to say; while it is hard to kill something one way, adding another method usually does the job perfectly. There have been quite a few "boil water advisories" over the years for crypto because boiling does the job easily (actually pasteurization temps are only needed IIRC). A 1 micron filter (absolute) will also do the job, as will a DE filter (pool) or (my choice but not portable) a slow sand filtration system. A portable UV device (steri-pen) might be the best bet for an on the go solution, or a rocket stove or a kelly kettle can make boiling water a lot more efficient.

Of course it all comes down to where your risk tolerance is and the situation. Any one method such as chlorine will kill the vast majority of nasties and if you are healthy that will likely be enough. While I don't worry so much for myself I know what it is like for people who are a bit older or children and it aint pretty.

From the same wiki article


> Immunocompromised people, as well as very young or very old people, can develop a more severe form of cryptosporidiosis.
> ...
> With transient infections diarrhea ends within 2 months and Cryptosporidium is no longer found in the feces. Chronic diarrhea is diarrhea that lasts for 2 or more months. The most severe form results in the patients excreting at least 2 liters of watery diarrhea per day.[2] They can lose up to 25 liters per day.


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## RossA (Oct 9, 2008)

Amazing what you can learn if you ask a question and sit back and listen! Thanks, guys.


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## LincTex (Apr 1, 2011)

cowboyhermit said:


> ... or (my choice but not portable) a slow sand filtration system.
> 
> A portable UV device (steri-pen) might be the best bet for an on the go solution,


I have both of these. 
I agree, the slow sand (actually mine is a BioSand filter - better) will be the ticket.

Ross, do some time searching for this device:

" biosand filter "

There are a lot of good .pdf's available that I have downloaded over time. Check it out.


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