Water filters in the real world.

[havingagiraffe]

http://www.bushcraftuk.com/community/showthread.php?t=10554&highlight=water+filter

Would you trust any lightweight portable water filter with Indian tap water?

I quite fancy the Pre-Mac...

 

[spamel]

As long as you boil it afterwards, yes.

 

[John Fenna]

And add iodine...

 

[British Red]

hag, (ooh thats not good for an acronym )

Okay heres the thing. Chemical treatment kills most micro organisms (bacterial and viral) but the hard coating of some cysts and protozoa resists chemicals.

Filtration will remove the cysts and protozoa but may not trap all micro organisms.

Chemical contaminants (e.g. pesticides or heavy metals) are harder still - boiling or chemicals won't touch them - high tech filtration or such techniques as reverse osmosis are the only way to remove them (sorry I'm getting boring now)

So you have a variety of options. Chemical treatment will kill micros and in many locations thats okay

Filtration will remove protozoa and cysts and the right sort (activated carbon or silver carbon) will also kill micro organisms

As for the real chemical nasties, you really need to do your homework. There are filtration systems that will remove them, but they are neither cheap nor particularly easily portable.

Given your scenario, a ceramic filter with an activated carbon pre-block should be fine

Happy to answer complex questions vis PM to avert boredom

Red

 

[British Red]

And add iodine...

Sorry for the boring warning - iodine should be avoided by anyone with a thyroid condition or who may be pregant - puritabs or hypochlorite based treatments are prefrered in these cases (sorry for being dull)

Red

 

[ArkAngel]

It depends on what you would call lightweight?

I have the military version of the premac and have used it all over the place in some VERY dubious water sources and have been fine.

I would still prefer to filter the muck out and boil but that is not always practical

 

[gregorach]

I believe the Pre-Mac pocket filter is issued in NATO survival kits, and has been subjected to some fairly serious testing.

 

[faff]

I have an msr and a katadyn pocket I use them more in the summer but I much prefer the katadyn its a lot quicker.I put iodine in first then purify the water to take out the taste.

 

[C_Claycomb]

Aquapure purifier bottle from www.bwtechnologies.com. Used one to provide all drinking water on a 9 day trip in hot summer conditions. No pumping needed

 

[Tiley]

Boiling's best but, if you're in a hot country, drinking hot water is not a particularly attractive when you want to quench your thirst. Filters are OK but you'll still need to zap it with iodine (Yuck!) or chlorine (fine if you like drinking swimming pools). Alternatively, splash the cash and try a SteriPen. Really good and water is potable in a couple of minutes. The kit comes with a bottle that has a rudimentary filter on it for keeping out the silt and grit. Only hiccough is that it's battery powered.

 

[Raptordog]

Any of you guys tried one of these.........

http://cgi.ebay.co.uk/HYDRATION-PUR...0089960QQihZ014QQcategoryZ97045QQcmdZViewItem

They also do diffrent versions and other types of purification systems

 

[gregorach]

[...] Filters are OK but you'll still need to zap it with iodine (Yuck!) or chlorine (fine if you like drinking swimming pools). [...]

The filter element in the Pre-Mac filters contains an iodine resin, so they filter and sterilise in one. They do leave an iodine taste in the water, but that can be combated by neutralising tabs, which are just soluble vitamin C.

 

[C_Claycomb]

The Aquapure uses iodine, then has a filter that removes much of the iodine flavour as you drink. After the first canteen or so I didn't even notice. The nice thing is that it can be filled quickly and easily from many sources without the need to spend time pumping. Also, the filter is a LOT more compact than Katadyn models. I know someone who did testing of filters/purifiers for the military and he reckonned the Aquapure was the dog's do-dads. I have to say that I agree. I would choose it ahead of the Premac even if I was given the little pump for free.

 

[Spikey DaPikey]

Any of you guys tried one of these.........

http://cgi.ebay.co.uk/HYDRATION-PUR...0089960QQihZ014QQcategoryZ97045QQcmdZViewItem

They also do diffrent versions and other types of purification systems

I've got the normal size "drink bottle" one, with the iodine in the filter. Not really used it in the wilds, but it looks good to me, and the data sheets make good reading !

Not much help am i ?

 

[leon-1]

Right the Pre-mac doesn't just filter, it's a purifier as well. It will filter and chemically treat at the same time, although I classs them as an expensive piece of kit I would also say that they are easy to use and reliable (when they cannot do the job they stop).


Yes they would be good to use in places like india, personally I use a Kayadyn mini and then treat the water after, in the long run it's cheaper (I'm a cheapskate and can't help it), but if you have an intolerance to specific chemicals the Katadyn is also the better choice as you get to choose what chemicals you are going to use.

When I get back home (Thursday night) I can discuss filters in more detail if you so desire.

 

[havingagiraffe]

As long as you boil it afterwards, yes.

 

[havingagiraffe]

And add iodine...

 

[gregorach]

Right the Pre-mac doesn't just filter, it's a purifier as well. It will filter and chemically treat at the same time, although I classs them as an expensive piece of kit I would also say that they are easy to use and reliable (when they cannot do the job they stop).

Yeah, I'd agree with that assessment - although I'd add that they're not very quick. I generally reckon on about 5 minutes pumping for 1L.

The one big strength of the Pre-Mac pocket filter is its size and weight. OK, two big strengths... (What, you didn't expect the Spanish Inquisition? ) It really is pocket-sized, and I'm not talking big pockets here.

The only problem I've had with it is losing the rubber dust caps...

 

[havingagiraffe]

Thanks to everyone for the good advice and offers of help via PM. :You_Rock_

I'm a total cheapskate, so I think it'll be a case of using the kettle and a perhaps a drop of iodine when bottled water's unavailable. Unless Ed wants to lend me his treasured pre mac, '58 pattern canteen and Crusader cup set....

Incidentally, when I was looking at water filters on t'internet, I saw a few places selling iodine in little 25ml bottles for about a fiver. Most high street chemists will sell you a half litre bottle of iodine for the same price, and might even throw in a dropper bottle if you ask nicely...

 

[Stuart]

no real need to filter third world tap water, just treat it with chlorine or iodeine (polar pure is by far my favourate method)

if you don’t like the taste of the chemical treatments, neutralise the chemical after it has had enough time to do its thing by adding a citric acid or a effervescent Vit-C tablet and the water will taste nice again.

you could boil it but it can become tiresome and uses fuel

if you want you could use a mechanical purifier (which removes viruses rather than a filter with just removes cysts and bacteria) but it has no real benefit for tap water over the simple chemical treatment and means more to carry and more to break