Water purification tabs

[admin]

Hey guys,

I’m finally getting around to finishing building my home FAK/survival kit.

I’ve got a good base first aid kit cheep to fill out the odd stuff I didn’t have like knuckle bandages and provide the bag. And I’ve stocked it with the items I want for first aid, as well as spare meds, survival blankets and so forth.

My one hiccup is water purification. I want to include this mostly for earthquakes when the mains water becomes questionable, and I got some that sounded promising called Aquatabs. Each tablet is meant to purify 20-25L of water, which means I would have enough for a long while or a few people, but I’ve become worried that I won’t necessarily be able to find a clean container for that large a volume of water.

I’m wondering if I should buy some tablets aimed at purifying 1 or 2L volumes as well. They seam to be a lot more expensive and money is tight so I was hoping to get buy with what I have but now I’m having doubts.

I know I can just buy a buy container 20L container of water and keep it with the kit if I can find room in the cupboard but it won’t be transportable and it won’t necessarily survive a quake intact anyway.

The smallest I think I could cut one of the tablets I have up into is quarters, which is 5L, which is still a large size to find a container for, especially one that will seal.

Any thoughts/help would be great.

[admin]

There are a lot of ways to purify water. Chemicals are only one of many viable solutions. Additionally, care should be taken to evaluate each purification method’s strengths and weaknesses, as well as note the level of purification you need: vs. bacteria, parasite, virus, or chemical impurities.

Even in chemicals there are a few variants: bleach, which is not considered effective vs. cryptosporadium, but is cheap and easy to obtain (warning: bleach will expire and lose effectiveness over time: be sure to have fresh bleach); iodine, which is very effective but not meant for long term usage (according to Potable Aqua, not more than 6 weeks); chlorine dioxide (such as Aquamira or MSR Miox), which is the more expensive of chemical solutions but extremely effective and safe for long term usage.

Then there is light treatment such as Steripen, using UV to render parasites, bacteria and viruses harmless, which works quickly but is ineffective in cloudy or murky water and can only be used on small batches of water.

There is also filter treatment, using finely perforated ceramic or fiberglass filters to filter out parasites and bacteria (but not viruses found in heavily contaminated or 3rd world water) combined with charcoal to remove chemical impurities. Some names include Katadyn, Sawyer, and MSR. Some are hand-operated (with a pump) and others work based on gravity. Iodine-membrane filters can be found that are effective against viruses as well but suffer a similar usage restriction as iodine drops or crystals.

Finally, you can boil or make a solar still. Boiling requires fuel and a solar still requires space. But these are also simple and inexpensive ways to purify your water.

Short answer: if you are going to go with chemical treatment, the #1 most recommended amongst long distance hikers is Aquamira or similar chlorine dioxide drops (offered by Katadyn, Potable Aqua, and several others), which are safe to use for long periods of time, effective against water-borne pathogens, and not extremely expensive. They are, however, more expensive than the other two main forms of chemical treatment but offer far less downsides. The same advice to long distance hikers seems to apply in your given scenario, since it sounds like you are looking for: compact, affordable, usable for small containers.

[admin]

Carrot already covered a great deal. A good idea with any kit is a stainless steel container that will allow you to boil water.

[admin]

You’ve got to define your parameters.

Sterile doesn’t mean disinfected doesn’t mean purified.

Water can be contaminated with chemicals that make it bad to drink – even from ‘natural’ sources….oil or bitumen seeps, heavy metal contamination, etc. Even residue from chemical disinfection (halomethanes, for example, from chlorinated disinfection agents). A compressed carbon block filter is your best bet for those kinds of problems, although it’s still problematic.

‘Sterile’ means REMOVING (not killing) any pathogenic (disease causing) organism (formerly living thing, which includes viruses in this context). Difficult to do and usually not needed. Note, even very fine (fraction of a micron) filters will not remove everything…but they usually remove enough.

Disinfecting water means killing (not removing) pathogenic organisms. It can be done several ways, using heat (boil, solar disinfection), chemicals including halogens like chlorine or iodine, or other chemicals.

Here’s a paper I wrote on the subject…still pretty good, but it could stand an update: http://www.scribd.com/doc/26369449/Sterilizing-Water-Rev1

[admin]

Thanks for all the info guys, clearly I have a lot to learn here.

To clarify my intended use, I want to be able to make sure I have drinkable water for up to a week for 1 to 3 people in the event of a disaster like an earthquake. I would like to be able to pick up the bag which contains the kit I’m building and some spare clothes and move if I had to by it’s most likely I will be saying in my home or near it.

It seams to me in such disasters water remains on for the most part but is considered unsafe to drink without treatment or boiling. Since power will most likely be out I was leaning towards chemical treatment. I am confident I could find a way to boil water if I had too, it would just be a bit of work in what is likely to be a tiring and stressful time.

Nim

[admin]

For that much water filtration is probably a better option…figure an absolute minimum of 1 gallon/day for drinking, cooking and minimal hygiene, per person in temperate climates – much more in hot climates or heavy work situations. Chemical disinfection is best in small quantities at a time, and takes a while to be effective. It also doesn’t do anything about chemical impurities in the water, and a filter incorporating a compressed carbon block will.

And since water weighs 8.3 lbs/gallon (1 kg/liter) you can’t be very mobile moving a weeks supply of water around.

[admin]

For that much water filtration is probably a better option…figure an absolute minimum of 1 gallon/day for drinking, cooking and minimal hygiene, per person in temperate climates – much more in hot climates or heavy work situations. Chemical disinfection is best in small quantities at a time, and takes a while to be effective. It also doesn’t do anything about chemical impurities in the water, and a filter incorporating a compressed carbon block will.

And since water weighs 8.3 lbs/gallon (1 kg/liter) you can’t be very mobile moving a weeks supply of water around.

[admin]

When I was in Boy Scouts we used little bottles of Iodine crystals that I’ll probably put in my BOB someday when I get around to putting it together. All you had to do was fill up the bottle with water (it was very small), wait a few minutes and dump it in your quart size water container (not sure how big you could do with it, but we always did waterbottles) and wait half an hour for it to do it’s thing. The advantage is that is was just a small glass bottle and very light and treated a large amount of water per bottle.

[admin]

BennyJ said: ↑
When I was in Boy Scouts we used little bottles of Iodine crystals that I’ll probably put in my BOB someday when I get around to putting it together. All you had to do was fill up the bottle with water (it was very small), wait a few minutes and dump it in your quart size water container (not sure how big you could do with it, but we always did waterbottles) and wait half an hour for it to do it’s thing. The advantage is that is was just a small glass bottle and very light and treated a large amount of water per bottle.
That would be a Polar Pure. Great system since it has nearly unlimited shelf life assuming proper storage. Once you open it, the clock starts ticking, but it’s good for 2,000 quarts. As the Doc said, however, chemicals will only kill organisms – if the water is polluted with chemicals, it won’t do any good.

For home purification in a disaster scenario, I keep a Katadyn Gravidyn. For EDC, my kit has a Aquamira Frontier. I do keep some Polar Pure at home just in case 🙂

[admin]

BennyJ said: ↑
When I was in Boy Scouts we used little bottles of Iodine crystals that I’ll probably put in my BOB someday when I get around to putting it together. All you had to do was fill up the bottle with water (it was very small), wait a few minutes and dump it in your quart size water container (not sure how big you could do with it, but we always did waterbottles) and wait half an hour for it to do it’s thing. The advantage is that is was just a small glass bottle and very light and treated a large amount of water per bottle.
That would be a Polar Pure. Great system since it has nearly unlimited shelf life assuming proper storage. Once you open it, the clock starts ticking, but it’s good for 2,000 quarts. As the Doc said, however, chemicals will only kill organisms – if the water is polluted with chemicals, it won’t do any good.

For home purification in a disaster scenario, I keep a Katadyn Gravidyn. For EDC, my kit has a Aquamira Frontier. I do keep some Polar Pure at home just in case 🙂

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