water purifers

[gary27]

Can anyone tell me what is the best method they have found for water purifing whilst trveling through africa,I've looked water purifiers iodene and puri tabs but which is best?
Thanks

[markharf]

The reason you can't find "the best method" is that there is no "best;" there is only the one you prefer. Or rather, the one you prefer in addition to one backup.

Most travelers buy water in throwaway bottles. I try to do this as little as possible, so I carry a filter. It's been working well for me for twenty years and a hundred countries (plus countless trekking trips): limitless water wherever I go in fair safety with a bit of ongoing effort. Plus, I like to have water instantly, rather than waiting for chemicals to take effect.

Others prefer chemicals. I carry a little bottle of tablets in case of emergency, but I never use them and always end up throwing them away and buying fresh....which I never use.

YMMV.

Mark

[marky116]

Hi
search on this forum using water purification you will find previous threads on this topic I use a seagul with no extras apart from occasional boiling all good so far in india.

In-Home Water Purifiers and Micro Water Filters - General Ecology Alpha

[gary27]

I like the way you do this markharf its along the lines of how i want to do it as i'd rather not buy bottled water if i can help it.
I used to use puri tabs in the army and didn't like the taste and as i'm taveling with my kids would rather only use them as a last means.
but my problem is what make brand and type of fillter set up to use i've read about ceramic silver and charcoal fillters and a mix of all three.
As it not a cheap item and could be the differance between being healthy or sick i want to get the right one at the right price.

[oldbmw]

If you wear contact lenses it is worth getting a pair of spectacles in case either pure water gets scarce or your eyes start to reject the lenses.

[gary27]

good point my wife dose, Thanks

[m37charlie]

Originally Posted by gary27

Can anyone tell me what is the best method they have found for water purifing whilst trveling through africa,I've looked water purifiers iodene and puri tabs but which is best?
Thanks

I use Accepta chlorine dioxide generating tablets; each good for 4ppm in 30L, so each 220L tank takes 7. Then, the water goes through a Pre-Mac filtration system: 4 micron fleece filter, then iodine releasing resin, then activated charcoal filter which also takes out the iodine and chlorine dioxide.
If you have a vehicle with a tank then a double method of killing the bugs in the tank and also filtering them out, preferably in stages, provides the best insurance.

Charlie

[gary27]

I'm now looking at a KATADYN POCKET Its ment to be one of the best hand pump water fillters around,I've read a lot reveiws on it all posative but dose anyone here have one and are they really that good?

[gjackson]

The best way to approach cleaning water is to use three stages: filtration, chemical addition and filtration again. The first two can come in any order, but the final should be a charcoal filter to remove the chemicals that you added in step one or two. Some of the commercially available filters can achieve both filtration steps in one unit. The reason for the various stages is (as explained in the OJ article), there are various classes of bugs you are trying to remove. They are classed by size:

Large (cycts and protozoa) are easy to filter, but are very resistant to chemicals (on the order of 4 hours contact time with chlorine required to kill them)

Medium (bacteria) are hit and miss in a filter, some will filter some won't, but they can be killed by chemicals (on the order of 20 minutes with chlorine)

Small (viruses) are practically unfilterable, but are easily killed by chemicals.

For the Overland Journal test we used a bacteria cocktail. The reason we did not use viruses is mainly due to the hazard and the price. Sourcing a water born virus can be difficult and they are very expensive. Well, much more so than the bacteria. Since cysts and protozoa are easy to filter we did not use them in the test.

For my system, I use common household bleach at 2 to 4 ppm in the tanks followed by a 0.4 micron ceramic filter impregnated with silver as a bacteriacide and then a charcoal filter to get rid of the chlorine. The bulk water in my tanks is stored as it comes and I filter on exit. I did a water system article for OJ that explained that system as well. I'd avoid iodine in an overland situation unless it's a system like Charlie described above. Prolonged drinking of iodine in high concentrations can cause thyroid problems.

Feel free to shoot questions to me if you have them. I'll be doing a talk on water systems and purification at the Overland Expo in Arizona in April.

cheers

[grizzly7]

Graham I'd have to say it does help to filter first, since any chemicals may be inactive on viruses hiding in larger particles.

And as a suggestion on household bleach, use it in tablet form. The chlorine content is often quoted over a range for liquid bleach making accurate dosing a guess, so you dose according to the weaker %. Chlorine also evaporates at a rate determined by temperature among other things

[url=http://www.drlaundryblog.com/?p=144]Clorox - Dr. Laundry

The above being a Clorox US bleach manufacturers site, who also have an online dosage calculator. They vary their manufacturing dose during the year to acheive 6% six months after manufacture in your home, so what will it be after a few months in a hot vehicle?!

The tablets I have are the equivilent of 60ml of 2.5% chlorine content each, and have an 18+month shelf life. As I posted earlier I use Micropur Forte in the water tank since it has silver in it too, and is very concentrated making a mug sized tub good for 50000 litres!

[gjackson]

That s a little miss-leading. The WHO recommendation for killing bugs in water is around 2ppm. If I can hit 2 to 4ppm with ~6% sodium hypochlorite (active ingredient in bleach) then that should be pretty darn close. If there is a 1 to 2% difference in the bleach it will make very little difference apart from taste.

The tablets you are using are a pretty good idea for long trips. For shorter trips I have no problem with liquid bleach.

On filtering before, you are quite correct. Bugs can hide from chemicals in sediment in the water and avoid treatment. I do actually strain water on the way in if needed, but I don't consider that pure filtering. Sure I run the risk of a virus hiding in a particle, but if he's hiding there then he'll probably get filtered out along with the particle, and I won't have to worry about him. It's probably not the perfect solution, but it has worked very well for me, and I know the risks I'm taking. Obviously I do have to shock the system every now and again, which is also easy to do with bleach. My main reason for using bleach is the price.

cheers

[jimmystewpot]

We used a Katadyn water filter and found it to be excellent. I would recommend with any of the portable/hiking type of filters that you also bring some coffee filters to get any really fine dust out of the water before you filter it.. saves having to take the filter apart to clean it out so frequently.. and as Murphy is a bastid.. any filter will always need cleaning when its dark, cold or raining and your in an area surrounded by mosquitoes or rabid dogs... just a thought!.


However we have relied on Katadyn and have been very happy with the performance (e.g. we didn't get sick and it was fairly minimal effort)

[grizzly7]

gjackson could you point out which bits misleading since you seem to agree with most?

Bleaches in the UK and Europe that I've looked at for this purpose show a range of contents, I think usually 2-4%. I've not seen one before the US Clorex stating only one value of 6%? But their website says it varies anyway depending on the time of year it was made, the temperature it was kept at and how old it is. Thats a lot of things to take into account after a hot busy day on a trip when you need to rehydrate but have to mix up your bleach dose for 2ppm first. 6% to 2% between brands is a big chunk to be very aware of before you allow for temperature etc! Not very KISS?

BTW a lot of water tank manufacturers for campers etc would not be too impressed if you told them you were using bleach at all

[grizzly7]

Shopping trip today showed all available bleaches only state less than 5%, so not too helpful for dosing!

[pdriver]

Use a chlorine based solution or tablet for purification and a granulated carbon filter such as the General Ecology or even a cheap Brita, to remove the unpleasant chlorine taste. The result is bottled quality water without the environmental negative of discarded plastic.

I understand that Iodine, whilst it is an effective antiseptic, can also be mildly poisonous when ingested. This may explain why some people do not feel well using it. Perhaps an expert can elaborate.