So, Aquamira Drops Don’t Kill Crypto For 4 hours. What??

Where the heck have I been? Well, no Big Walk for 2012 sadly, but the project that I’ve been on about for years is under-way, though still in the early stages and still off topic for this blog! Though I’ll certainly do a post or two mentioning it at some point (there may even be a clue on Twitter eventually @RedYetiDave ) since it’s obliquely related to the outdoors…

I’ve been reading, with great interest, the excellent series of articles on on water treatment options (sorry, subscription only). There was a heck of a lot of info, as you’d expect from a series whose main author is Roger Caffin and which included Will Rietveld in the contributor list.

One really important point which made me pretty angry: Aquamira drops only kill cryptosporidium after 4hrs exposure.

What? So the main thing that I’m trying to avoid in the UK hills is actually not cleared by the drops in 30 minutes as they appear to say?

It comes down to the fact that Aquamira originally sourced the liquids from another company who’d only got EPA approval for bacteria clearance. So although it does kill protozoa (crypto etc) it takes longer than they mention in the instructions since the instructions are technically only cleared for describing killing bacteria (and viruses luckily). Grrr…

So after much thought, and reading reviews and blog posts, I’ve decided that the best option is a Sawyer filter. Why? Because they filter all bacteria and protozoa, which are the two main threats where I draw water in the UK hills and even the Alps. They filter water incredibly fast, you can drink straight from them, and are expected to last for four and a half million litres (a million gallons). Meaning it’ should be a once-ever purchase.

I never expected to even consider using a filter again, all that pumping and then cleaning and then pumping etc. etc… But the Sawyer filters use a completely new method: Hollow Fibre; which make all that pumping and cleaning unnecessary. They are essentially a set of straws which you push water through. Meaning their surface area is gigantic, so they don’t block for a long time. Also, when they do block, they can simply be back-flushed with an included syringe, or just from a tap (faucet). Which apparently makes them like-new immediately. The back-pressure very slightly enlarges the fibres, meaning the crud which is stuck in the pores is simply released.

They’re reputed to be very durable indeed though you mustn’t let them freeze, like any other filter. So keeping it in a sealed plastic bag in the sleeping bag for winter camping is necessary.

There are other companies which make filters using hollow fibre but they appear not to be anything like as good or durable as the original Sawyers.

I did also consider the Travel Tap but try as I might, I could not get the company, Drinksafe Systems, to divulge anything on the efficacy of the virus filtering, despite many emails and even phone calls with the owner of Drinksafe Systems himself. I got a couple of pages of reports which certainly looked good on clearing most things, but the line which I was told was relating to virus clearance was only mentioned as “F+ RNA” which from Googling appears to be a broad term which may be applied to virus reduction testing but may equally be applied to bacteria reduction testing.

I would love to think that the Travel Tap does what it says, I really, really want to use it, but without some more solid documentation from them, I’m going with the Sawyer since that’s something well investigated by Roger Caffin et al. (Sadly the Travel Tap isn’t mentioned as part of the series and when I asked Roger about it directly he’d not heard of it, and was scathing about any company who would not provide test results).

Perhaps I’ll eventually be able to get access to something solid on the Travel Tap’s virus filtering but until then, I’ll stick with the Sawyer.

If I feel the need to also be sure that I’m killing viruses after using the Sawyer I’ll use either a Steripen Adventurer, or of course the Aquamira drops!


14 Replies to “So, Aquamira Drops Don’t Kill Crypto For 4 hours. What??”

  1. I’ve never tried water treatment besides boiling, but I think that would change rapidly if I hiked in the British Isles. Good to know about this Sawyer filter, it looks like a decent piece of gear.

    But hey, for Winter and freeze damage to the filter, try Glycerol. Should be easy to find, you can empty the filter as much as you can and throw in a few ml of glycerol, which should keep any residual water liquid down to -30 C, or even below.

    Pretty decent amount of energy in it too, so you can count it amongst your food items as an energy drink. And you can use it topically to treat dry skin, as well as a pretty effective antibacterial.

  2. Well, well. You’re still with us!

    So then – what’s this new projects, Dave?
    I had never heard of the Sawyer filter, so I shall have to dig one out for the Pyrenees. I’m not too fussy about water in the UK as I’ve never encountered a problem with it, as I’m quite careful in choosing my source.
    So – thanks for the Heads up on that.
    And, get out for a walk!

  3. Hi Alan!

    Ah, new project is off-topic – but exciting (for me! ;)

    Yes I am always careful with sources, probably why I’ve never managed to pick up any crypto despite not actually treating for it after all!

    But what changed my mind was a solo walk on a hot summer’s day where I walked for a good couple of hours past the point where I wanted to stop because I couldn’t find any sources I trusted. If I’d had a way of purifying the water I did find it would have been a far less unpleasant end to the day’s walking.

    Plus the fact that crypto really is common around livestock (I see a lot of sheep on the hills when I walk!) and it’s a “single dose organism” meaning that unlike bacteria, you only need one of them to get into your gut and you become host to countless thousands within hours, and may fancy a stay in hospital. Not massively likely perhaps but nasty enough that I’d rather avoid it!

  4. Thanks Dave. Definitely useful to know, don’t fancy ingesting any crypto or other nasties. I like the idea of a filter better than purification tablets, as I try to avoid, where possible, drinking even small quantities of chemicals. You’re right though that all that pumping isn’t fun so the Sawyer filter seems like a great option :-).

    1. I’ve yet to try it out properly… but it seems nice and light. Much easier than the Aquamira. Though combining it with Aquamira where there’s a virus concern means you can actually take advantage of the half-hour kill time for viruses (and be sure to get everything since the water will be clear of particulate come to think of it) so it’s not made it completely redundant! :)

  5. I was interested to read your comments about the travel tap. I use drinksafe systems inline filter that uses the same system ad seems pretty equivalent to the sawyer system and it is stated to remove cryptosporidium as well as at least some viruses. Their published data here I just wondered, did you find this inconclusive or am I missing something? I’d be interested to hear of any concerns as it is a system I’ve come to rely on but I don’t want to get sick by contracting something I’ve not taken account of. Thanks and best wishes. Jim

    1. Hi Jim!

      I am not saying for a moment that the data they are referring to isn’t real. But I just could not verify the virus claim that’s all.

      I’m sure it is equivalent to the Sawyer but my point is that they say it’s better; it removes viruses.

      Since I can’t verify that, despite great effort, I do not trust them enough to use them personally. That’s all.

  6. Dave, interesting to find your site and feel there is much valuable information here.

    I’ve used Traveltap for several years in south UK filtering horrid looking water from troughs found in fields. The big problem for me was the poor throughput, and a horribly smelly squeezy plastic water bottle which tainted water stored in for any length of time. Very frustrating in use at the end of the day when you need a couple of litres for drinking and cooking.

    I just ordered a Sawyer kit. I hope you will get some commission on this! ;-)

    1. I wish I got commission! But I’ve only played around with the filter at home so far (other projects on the go…). Looks good though.

      Interesting to hear your comments on the TravelTap. I’ve seen videos showing them filtering very, very slowly and others showing them filtering fast. I have a feeling they’re meant to be fairly fast so I guess it might be a quality control issue.

  7. I’ve now received my Sawyer system and I see they specifically claim that they do NOT protect from viruses, unlike Travel Tap! I should have studied your discussion a bit more closely.

  8. Oh dear! But where are you taking water?

    The virus threat in most of the developed world isn’t considered to be very large and as I mentioned above you can always use Aquamira or Steripen if you’re in an area where there might be a risk.

    But obviously that’s my main problem with Travel Tap – they make the very unusual claim that they deal with viruses but can’t seem to back that up with anything very solid so I personally wouldn’t be trusting one if I was in an area where something like cholera was a threat.

  9. Hi Dave, I try to reach you this way because I couldn´t find an e-mail.
    I started a blog about the nature of the Cantabrian Mountains (northern Spain), which will have a lot of information about walking and landscape, and also about wild flowers (orchids), animals and geology which can be found in this region.
    I think those mountains are a lovely place for walking.
    The link is:

    I invite you to have a look, and if you think it´s worth it, I would appreciate a link from your website.

    Sincerely yours,

    Marius van Heiningen

    1. Wow – that is gorgeous country Marius! Thank you for sending the link. I have in fact added you to my blogroll (long time since I did that – and don’t usually respond to outright requests!).

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