Water Purification

[Martyn]

Hi Martyn, I don't know about other systems but the PreMac PWP and the PreMac SWP do take out viruses. Ok the SWP is a pump, but then to some extent so is the Lifebottle, but the PWP is gravity fed.

Check the details. The pre mac deals with viruses by disinfection using an iodine-resin complex which acts as a contact microbiocide. It doesnt "filter" out the viruses, it kills them with iodine. Like I said, to my knowledge, the only portable filtration system that produces genuinely sterile water without using chemical additives in one form or another, is the lifesaver bottle.

 

[Martyn]

Having said that I do really like the look of the Lifebottle, even though having read the instructions it doesn’t seem quite as simple to use as the videos seem to say. The one thing I’m wary of is the risk of contaminating the clean water from the drinking vessel itself. The whole unit is immersed in dirty water to fill or if it is poured in there seems to be a lot of spillage, and although the actual drinking mouth piece is under a water proof cap, to uses it immediately I would have thought there is a risk of getting a few drops of dirty water from the outside bottle mixed in. Other than that it looks brilliant, does anyone use one?

Yeah, I've got one and you do have to be careful. However, a quick wipe removes the risk of run-off and then when you pop the cap, the water comes out under pressure. It doesnt dribble down the side, you get a jet of water out of the nozzle at the rate of 2.5 litres/minute, you just direct the jet into your mouth or a cup or whatever - no contamination.

 

[Martyn]

This is worth a watch....

http://www.youtube.com/watch?v=4tm9tFvu6g4

 

[andy_e]

You may use solar disinfection as a your preferred method (first one to look up)

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

Interesting stuff, if you have the time to set up and can leave it for long enough ... might take a while up here in Scotland on all but the rarest of summer days.

Sorry if I'm going a wee bit off topic but these look interesting too ...

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

 

[AJB]

Martyn, no offence meant mate.

I simply thought you were implying no other system removes viruses. Yes neither of those systems filters out viruses, but the treatment they automatically give the water, kill viruses two to five minutes after filtration.

By filter I thought you meant “water cleaning equipment” and not specifically just a filter process.

Andy

 

[Martyn]

Martyn, no offence meant mate.

I simply thought you were implying no other system removes viruses. Yes neither of those systems filters out viruses, but the treatment they automatically give the water, kill viruses two to five minutes after filtration.

By filter I thought you meant “water cleaning equipment” and not specifically just a filter process.

Andy

Hey, no offence at all mate.

The premac is an excellent filter and a good choice if you are happy with the chemicals. It's a good packable size too. One of the downsides of the lifesaver is it's size and weight. Compared to the premac, it's big and heavy. So for some people may be preferable. I think the lifesaver is great though. No chemicals, all done by filtration alone, produces genuinely sterile water, easy to use and a very high flow rate by comparison. It's also very expensive, although you can get em on the bay for a low as £50 now (they were £300 when they first came out).

My big want at the moment is a lifesaver jerry can, but they have only just come out and are still very expensive. There is a big military contract for them though, so they should hit the surplus market in time.

 

[AJB]

Good

Yeah, I was looking at the Jerry can, and although it's a chunk of cash at £200, for what it is, its quality and how long it will last I think it's really good value for money.

And to be honest I don't think the bottle is expensive when you look at the price of the competition of equal quality, add the price of a good water bottle, it's about the same, and it's not much bigger than those two things together.

 

[Teepee]

All other portable filtration systems will remove bacteria, but they wont remove viruses so you have to treat the water with something in addition to the filter.

The webtex system/drinksafe system specifically states that it kills viruses.

 

[Paul_B]

No expert but IIRC puritabs have two types, one for keeping water fresh and one for killing bugs. Might be wrong but I remember seeing one make of sterilizing tabs one was the something pro version which killed bugs the other just kept water fresh for storing for a while.

Very few filters kill virus' although in the past they said they did. Now the likes of Katadyn filters no longer mention taking out virus'. Drink safe filters such as travel tap and their inline filter. I hear a lot of good things with these since they allow you to rig it up directly to a drinks bladder to either drink dierctly or to do a gravity feed to a second bladder for actualliy using.

Steripen is a techie option based on the technology used in water treatment for tap water. Battery powered though.which is always a weak point. I bought the standard version and used it for one long trip over two weeks and needed a second set of batteries (4 x AA) at about 8 days. Not too bad. However I took it out for a second trip and no matter how many new batteries I tried it wouldn't work. A most expensive waste of money. I personally think it is too fragile.

The premmac travel wells seem to me to have a short life i.e. produce fewer litres of good water before they are no good. They don't do virus' like most other filters but has been pushed a bit by Ray Mears so will sell to some on that basis.

Katadyn has a new inline filter I think that seems good.

Lifebottle - Well I first saw it at the Outdoors Show 09 and thought it to be an expensive and very heavy piece of kit. If you are carrying that weight then I'd rather just boil it and leave it to cool. I mean at the weight penalty of the life bottle you could have a feww 1litre pots on a fire boiling and coolingn for your drinks bottles.

I don't know how relevant it is to most people on here but IIRC it is possible to be at an altitude where water boils at a lower temperatures than is needed to kil bugs. Just thought I'd throw that inot the mix.

In the UK most higher streams are likely to be clean enought to drink straight from the stream. I've done that for years. Usual caveats such as don't blame me if you get ill, check the stream above for dead sheep or toilet paper, take water from streams flowing into lakes and tarns not out of them and take it as high up the hillside as possible.

Also it has been suggested that most cases of "bad water" in the hills has probably come from poor hygiene. You go to the toilet do you wash your hands with soap sufficiently or use alcohol gel well enough. By that I mean alcohol gel states it kills 99.9% of nasties but that is on clean hands and if it is used well. It is likely to be much less successful in the hills due to dirty hands etc. Afterall it needs the alcohol gel to hit the bug to kill it. If your hands are dirty or the dead skin cell layer is thick the bugs can be hiding and not be in contact with the gel. Also cleaning your hands with soap and water relies on you taking the dead skin layer off with each wash hopefully taking the bugs with them.

In light of the above it is only part of the story to clean your water you have to keep clean yourself. And if you do get ill don't assume it was the water!

 

[wentworth]

Ahem, as stated above, the Sawyer does claim to filter viruses out.

 

[Pict]

That one went into the image file, very illustrative. Downright rude to do your dying in potable water.

Boiling is good but time and fuel consuming. I use a small home made filter and then treat with iodine or chlorine. I have never had a waterborne illness.

Mac

 

[Martyn]

The webtex system/drinksafe system specifically states that it kills viruses.

Yeah, guess what - it's impregnated with iodine. Doesnt filter viruses out of the water, it theoretically kills them with iodine. I say theoretically, because iodine requires time in contact with the water for it to do it's stuff, so assuming you squirt the water into a glass and wait for a bit before drinking it, it should work.

 

[Martyn]

Ahem, as stated above, the Sawyer does claim to filter viruses out.

Never heard of it, you got a link?

If you mean this one...
http://www.sawyerproducts.com/SP149.htm
Then it doesnt remove viruses. It has a 0.1 micron filter which is fine for bacteria, but to remove viruses, the filter must have a pore size of 0.025 microns or smaller.

 

[wentworth]

Hi Martyn,
this is the one I was thinking of:
http://www.sawyerproducts.com/viral.htm

claims a 0.02micron rating

 

[Martyn]

Hi Martyn,
this is the one I was thinking of:
http://www.sawyerproducts.com/viral.htm

claims a 0.02micron rating

Yep, you're right the filter is small enough for viruses. Dunno about flow rates and wotnot, but it certainly does claim to have a fine enough filter.

 

[wentworth]

The flow rate isn't that great apparently for real life water usage, I would think with a filter that fine, it'd clog fairly easily, though I understand you can backflush them.

 

[Martyn]

That's always gonna be a problem with super-fine filters. You cant backflush the lifesaver, but it handles the problem by having progressively smaller pore sizes, like a series of sieves, so the big particles get removed before they get close enough to the small pores to block them. It's clever. All you do is periodically rinse it under the tap. Flow rates do reduce over time, but nowhere near as bad as charcoal filters and the rated 2.5 litres/minute is pretty impressive to start with from a 0.015 micron filter system.

The other thing I like about the lifesaver, is that it's not an "on demand" system. That means you can fill up a few water containers with clean water in a few minutes, which means if there is 2 or 3 of you, you only need one filter to fill up everybody's bottles when you stop for water.

 

[sccadmin]

From what I understood you need to be careful about particle size when it comes to using chemical treatments. If the water contains large particles of leaf / soil matter or whatever else the bacteria / viruses etc may be able to keep out of the way of the chemicals and re-infect the water / be ingested. So with chemical treatments you should strain or at the very least take water from fast flowing and clear sources.

 

[lostplanet]

Rather than start a new thread, Am I right in thinking that any water source in the UK
ie ditches, puddles, rivers, streams, quarrys it's ok to take that water and filter it with a mill-bank bag then boil it with a rolling boil for 2-3 minutes and it will be safe to drink and store in a water bottle?

and if you cannot boil for any reason then water purification tablets and/or iodine will make it safe to drink?

Sea water and salt water cannot be used as above?

 

[hertsboy]

Rather than start a new thread, Am I right in thinking that any water source in the UK
ie ditches, puddles, rivers, streams, quarrys it's ok to take that water and filter it with a mill-bank bag then boil it with a rolling boil for 2-3 minutes and it will be safe to drink and store in a water bottle?

and if you cannot boil for any reason then water purification tablets and/or iodine will make it safe to drink?

Sea water and salt water cannot be used as above?

No, it's not OK everywhere. The problem is thata chemicals used in agriculture and industry may have entered the water, and these are not removed by filtering and boiling/purification tablets.

Or am I wrong? If so, I stand to be corrected.

I do most of my walking in the hills above the farm line - and have had no trouble with water there - but I always boil it or use purification tablets.

I am walking part of the Pembrokeshire Cost Path next week -all of which is through agricultural areas. I must say I am very concerned about taking water from streams there - even with water purification tablets. Luckliy there are plenty of villages and cafes where I can get water supplies.

I think John Fenna, who lives in the County, has thoughts on this - what would you advise me to do John ?