Water Filtering/Purification – Which to choose?

I can rave about the Platypus gravity filters. Fast (approx. 2 liters/minute), easy to backflush, reliable, and simple. Plus you can fill up the dirty water container and hang it in camp or transport it. Not quite as light as the Sawyers, but better when treating water for more than one person. My complete Platy setup (2-l dirty bag, tubing, filter, blue bottle adaptor, and carry case) weighs 8.4 oz. I am willing to trade a few ounces for ease of use and lack of fussiness. Have run about 100 liters of water through it with no issues so far. Very happy.

You may not be looking to get into ultralight backpacking at the moment, but as you go you may find your opinions have changed.

I personally don't use any filter. Instead, I use Aquamira Water Treatment Drops. There is some debate of whether or not they add a "chemical-like" taste to the water. I don't detect the taste when I drink it. Repackage it into a couple small containers and you'll find it to be very convenient.

I have looked into drops and tablets, however I get hung up on a couple of things.

– The ones I have checked all takes hours before they kill anything/everything.
– Any "dirt" from the water source will still be present.

Maybe I am just not really thinking it through?

—

@Jenny – thank you!

You're probably overthinking it.

It may take hours to kill "everything", and some forms cannot be killed with it at all. However, you're very unlikely to have anything harmful in it after about 30 minutes as long as you're smart about where you take from. For example, stick to flowing water instead of still or puddle water. Check the close proximity for anything in the water (dead animal, etc). If you stick to common sense, you should be fine.

If you feel the area may not have reliable flowing water, then maybe I'd opt for a filter. At the moment I've never had the need.

Got it, thank you!

I will do a bit more reading on the trails I have here locally and how the water stacks up. Being it PA there is running water nearly everywhere do tabs or drops may be the best solution indeed.

A few things to remember:

You do not filter viruses. Ever. They are too small. .02 microns is the standard for most backpacking filters – not all of them, but most of them. You'll be able to filter out most bacteria, but there are rarer ones that are even smaller than .02 microns.

There are purifiers like First Need that will take care of viruses – through chemical means, inside the replaceable cartridge.

No filter or purifier on the market will remove all minerals or chemicals – most remove hardly any at all. So careful choices of water sources is ALWAYS necessary – being aware of mining or ag activity upstream of you is a good thing. Don't try to filter those mineral springs you can sometimes find and expect to remove the molecules – it won't happen. Reverse Osmosis in portable form isn't possible, so neither is purifying water of toxins or minerals.

Boiling is the most effective way of purifying water, but is fuel intensive, slow, and not usually used.

SteriPens kill nothing – but they scramble DNA so the live things you ingest won't reproduce in your gut, and die childless. So then you don't get sick.

Many thru hikers will use a combo of a cheaper, less effective filter, such as the Aqua Mira Frontier Pro – that strains out cysts and larger things like protozoa, leaving only things you can kill with chemicals easily, in 30 mins or less.

At the moment, I have several filters – which one I take depends on where I'm going. A pump with a really good prefilter for shallow, potentially dirty water. A Sawyer Squeeze with a large Platypus or a Platypus Cleanstream the rest of the time.

I have a few Micropur tablets to back up mechanical means, as mechanical things can and do fail/clog. And then? My backup is to simply drink the water. Most of these things have an incubation period. Better to be sick in a couple weeks than dehydrate yourself to the point of being Really STUPID and making a long chain of mistakes in the backcountry while Search and Rescue is looking for you.

I have been using Aqua Mira for years, throughout the Grand Canyon. I've never gotten sick. Although I usually let the water sit for more than the specified 15 minutes – not on purpose, but just because I treat a bunch of water at a time and don't drink it all right away – I sometimes drink it sooner. There is no discernable taste.

I know you said ultra-light isn't important to you, but a full set of AM bottles weighs about 3oz – less if you decant a smaller portion to other bottles. And of course it's super-compact.

The one big drawback of AM is that it doesn't filter out particles. Of course, you can just use a coffee filter to do this. And if you're trying to suck up water from pools that are only an inch deep, a pump is nice to have.

LifeStraw claims their system handles 99.999% of viruses in addition to 99.999% of bacteria and protozoa.

"The durable water purifier removes 99.999% of viruses including Rotavirus and Hepatitis A. Additionally LifeStraw® Mission removes 99.9999% of bacteria (E.coli, etc.) and 99.99% of protozoa (Giardia, Cryptosporidium) and it reduces turbidity (muddiness) up to 0.02 microns. With this comprehensive level of purification, LifeStraw® Mission eliminates the need for iodine or chlorine tablets to purify water and provides the additional protection of virus removal."

Link: http://www.buylifestraw.com/en/press/item/new-lifestraw-mission-is-the-first-gravity-powered-water-purifier-to-remove-bacteria-protozoa-and-viruses-from-backcountry-water

Am I missing or misunderstanding something?

Regarding the sawyer, why not filter the water at the stream during a break and carry it clean so when you are ready to use it is all good to go? It takes me just a few minutes to fill up my 70oz bladder.

Wouldn't that kinda defeat the purpose of the Sawyer?

If I have to bring another bag, possibly hose, etc. wouldn't I be better off just getting the Platypus or Lifestraw?

Filter / purifier options are numerous. I think a better way to approach this problem is first decide which of the following do you want your device to do? Then, I would pick the simplest/smallest/lightest option that will do the job effectively and reliably within my budget. So…

Water treatment can cover any or all of the following 5 aspects. Tell us which ones are important to you:

1. handle viruses
2. handle bacteria
3. handle protozoa cysts (crypto, giardia, etc.)
4. clarify water
5. improve water taste

Put water in a clear plastic bottle for a day in direct sunlight and the UV will kill most things in it. A lot of African people rely on this effect to stay healthy. A heavy solution if you're on the move, but worth remembering for if you have a base camp for a few days.

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

High energy ultraviolet radiation from the Sun can also be used to kill pathogens in water. The SODIS method uses a combination of UV light and increased temperature (solar thermal) for disinfecting water using only sunlight and PET plastic bottles. SODIS is a free and effective method for decentralized water treatment, usually applied at the household level and is recommended by the World Health Organization as a viable method for household water treatment and safe storage.

The method of using PET or glass bottles to purify water with UV light is called SODIS. There are lots of scientific papers written about the process and its limitations based on latitudinal location, altitude, cloud cover etc.

Very interesting stuff.

Hi Ben-

Ideally it would be 1, 2, 3 & 4.

It would be nice if it improved the flavor, but that is far from a priority.

While I understand getting sick from drinking the water in the US is relatively low I am still looking for a solution that is rather bomb proof. I have been sick more than once from drinking water while traveling abroad and I would like to avoid repeating it especially when the only means of transport is my body.

Maybe I am completely paranoid, but past experiences like those are hard to forget.

I’ve been using this exact method for quite a while now, having treated some very nasty-looking, standing warm swamp water on a couple of occasions without getting sick.

Quick clarification in this thread….

Most filters go down to around .20 not .02. A filter going down that small is actually significantly more effective than nearly anything else.

Personally, when I'm unsure of water quality I used a bottle with a built in filter by Katadhin. It goes down to .03 if I recall correctly, and, at least in North America, I'd use it anywhere at that level.

That helps a ton, thank you!

No problem!

Any of those filters designed for third world country use should get most anything, even some heavy minerals. Even so, if you camp around cities, it might not be a terrible idea to use one. Who knows what's floating in some streams close to large city run off.

@Lane:

For Backcountry Use

Given your preferences #1-4… take a look at the Aquamira Frontier Max. For what it does (#1-#5 actually) — this filter is very cheap, small and light!

No direct experience, but my “go to” filter is the next model down — Aquamira Frontier Pro — and I’ve been very happy with its versatility and ease of use. I recommend the more expensive model because that one can handle viruses as well. It’s also the model I will be upgrading to.

For Hosteling / Traveling Use

You mentioned having gotten sick when traveling… for travel use, I highly, highly recommend Steripen water purifier — either the Adventure or Freedom model. I’ve been using it on world travels since 2009 — going to third and even ‘fourth’ world countries for months at a time — and never got sick once! It’s a lot easier to whip out this thing and stir for a minute or two — then to put together a pump filter. Imagine working your pump filter inside a restaurant!?!

Lori P:

"You do not filter viruses. Ever. They are too small. .02 microns is the standard for most backpacking filters – not all of them, but most of them. You'll be able to filter out most bacteria, but there are rarer ones that are even smaller than .02 microns."

This is incorrect. There are plenty portable water filters that remove viruses. Many backpacking filters do not, but those are 0.2 microns. Filters that are 0.02 microns are the whole different story however.

An example of the filter that removes pretty much all viruses *without* any chemical treatment:

Lifesaver

@Jonathon – Thanks again!

@Ben – Thanks a lot, I will check out the aquamira and will most definitely keep the Steripen in mind for my next trip abroad.

Love the picture of seeing me whip out a filtering system in a restaurant and standing there holding it for a few minutes :P

I am sure the staff would love that and the facial expressions of other patrons would be gold!

@Monkey – thanks!

A lot of good stuff posted!

“Am I missing or misunderstanding something?”

From your link, lifestraw claims:
1) “New LifeStraw® Mission Is The First Gravity Powered Water Purifier To Remove Bacteria, Protozoa And Viruses from Backcountry Water”
Well, First Need has been doing that for at least 30 years so I don’t understand Life Straw’s claim. And for the record, First Need doesn’t use chemicals to snag the viruses. Life Straw doesn’t either – however by a different method. So yes there are filters that filter viruses.

2) “Easy-to-clean pre-filter and purification cartridge”. I’m just thinking this is famous last words for all hollow-fiber systems.
3) It seems like this is a good system for a group with patience but overkill for 2 people. I.e., there are lighter options.
4) Since it is very slow (the slowest I’ve ever seen), this may be good for large camps but very awkward backpacking on the trail. With this system I see you carrying a LOT of water at a time
5) This is just my personal opinion (again). If you’re traveling abroad (as noted above), this looks like too clunky of a system unless you’re in one spot for several days and not backpacking.
6) LifeStraw Mission is 0.02µm. I see several studies that measured it. I.e., it’s not a typo.
7) What’s confusing is how can these filters filter out more viruses than the much larger protozoa? And I see independent studies verify this.This is just a curious question. How does this happen?
:)

Sorry, I spend most of my time hiking and not in camp so I have a hard time appreciating gravity-fed systems.

-Barry
-The mountains were made for Tevas

Thank you everyone for the feedback and advise.

I believe I will be grabbing the Aquamira Frontier Max and giving it a whirl.