Grayl Ultralight water filter

not cheap but looks effective;

http://www.thegrayl.com/why-grayl/

I looked at those and found the Sawyer squeeze lighter and cheaper and just as effective.

In contrast to the Grayl, Sawyer does *not* say that the Squeeze can do viruses -- so virus-wise, at least, the Grayl is *more* effective than the Sawyer.

Relating to usefulness if you're a winter hiker: neither filter, once used on a trip, has a field procedure for emerging unscathed from freezing temps. Last time I checked, only Katadyn claimed this capability.

I have noticed since hiking with my dog, that water is now critical to my hikes. Rather then carrying all my water or counting on natural sources for my dog, I need a filter. What would you recommend for me and my dog ? I use Nalgene bottles and the ability to use it in cold weather is a must. I've heard the name Katahdin for year's, is that the go to filter?

sierra said:

I have noticed since hiking with my dog, that water is now critical to my hikes. Rather then carrying all my water or counting on natural sources for my dog, I need a filter. What would you recommend for me and my dog ? I use Nalgene bottles and the ability to use it in cold weather is a must. I've heard the name Katahdin for year's, is that the go to filter?

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I just switched to the Katahdyn Hiker Pro this year from the Sawyer Squeeze and love it. The pump style really allows for getting water out of very small sources like the many springs in the Whites, tiny brooks, etc. I got 2L of water out of a spring on Katahdin this past July that was only about the size of a cereal bowl between some rocks. If I had my Sawyer Squeeze I would have been screwed. The Sawyer was fine too but you really needed a decent body of water to fill the bags without it being a hassle. I know a lot of people have also claimed the Sawyer and Katahdyn are equally fast but I personally find the Hiker Pro to be far faster than the Sawyer I had. The Sawyer is a super simple design that likely would never break and the Hiker Pro has more parts and potential for a field breakdown but I think the benefits outweigh this fact, especially in dry years where needing to get water out of tiny or stagnant bodies of water might be the difference between water and no water.

sierra said:

I have noticed since hiking with my dog, that water is now critical to my hikes. Rather then carrying all my water or counting on natural sources for my dog, I need a filter. What would you recommend for me and my dog ? I use Nalgene bottles and the ability to use it in cold weather is a must. I've heard the name Katahdin for year's, is that the go to filter?

Click to expand...

The Katadyn is a great and very popular filter, as is the Squeeze. As noted, the Katadyn is really fast, and the Squeeze is really light. Both are vulnerable to failure in the field, but you can back yourself up for the Squeeze's primary mode of failure (ruptured bag following a too-hard squeeze) by carrying a backup bag. If your trip plan critically relies on purified water, you should have backup, perhaps via the aforementioned backup bag for the Squeeze, and/or chems.

Seriously sub-freezing conditions present a challenge for filters: when wet, even if drained/purged conscientiously to avoid cracked housings and pump parts, the water remaining in their elements will freeze and render the filter useless. The Katadyn is the only filter I'm aware of that purports to tolerate this -- but only if it is indeed thoroughly purged of water so that all that remains is the damp element. In the case of the Squeeze, you'd have to keep the element on your warm person once you've used it. Even with this level of care, which itself is a challenge, if it's cold enough the element will freeze up faster than you can actually use and then purge the filter. Chems aren't a very helpful option either, as with icy water they require a long steeping time. So if there's no escape from serious cold and your plan relies on water purification, pack a cold-capable stove.

Alex

As has already been noted, any mechanical filter will be prone to freezing which will "clog" the filter and may damage it, but chemical methods (with long contact times) and boiling will still work. However, you might also consider a Steripen (UV disinfection)--the manufacturer claims that they will work in the cold. The main issue is how well the batteries work rather than the disinfection itself. https://www.steripen.com/istm/site/steripen-misconceptions/ And if you use lithium primary (AA, single-use) cells, the batteries should keep going at temps too cold for you to bring the dog (eg < -20F or so).

Note: Steripen's are available with internal rechargeable batteries or using AA batteries--get the AA version. https://www.rei.com/product/867414/steripen-classic-3-water-purifier-with-prefilter It can be used with lithium primary cells (for best cold weather performance) or NiMH cells (the rest of the time. (Lithium ion rechargeable cells have cold weather performance similar to NiMH cells.) Also, unlike many internal rechargeable batteries, AA batteries are field replaceable.

EDIT: Lithium primary cells (typ AA and AAA in consumer usage) have better low temp performance (useful to ~-40F) than either lithium ion or NiMH rechargeable cells (both useful to ~-20F). (The actual temp limits depend on the details...) Batteries can also be warmed before use to improve their performance. Alkalines are a poor choice for this application, particularly in the cold.

Doug

Thank you to the above three. I'm going to go with the Katahdyn Hiker Pro. Sounds tried and true, which I like.

I've also been poaching knowledge from this thread, so thank you.

A while, yardsale posted about his investigations into the steripen--perhaps you can find them with a search. (IIRC, he appeared to have some professional expertise in water disenfection.) Also IIRC, he concluded that it was an effective method.

There is no reason that one must use the same method of water disinfection all year around. It might make sense to use a filter in above freezing conditions and a more cold-tolerant method in below freezing conditions.

Doug

TJsName said:

I've also been poaching knowledge from this thread, so thank you.

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If you want more details I had asked a question about different filter types awhile back when I decided on the Hiker Pro and there was a lot of detailed information in it. I think the thread was called "Squeeze vs Pump vs Gravity" or something like that. I'm "thread search impaired" and can never seem to find a thread when I'm looking for it or I would have posted the link. I think it was late Spring I had asked the question.

Found it! http://www.vftt.org/forums/showthread.php?57620-Water-Filters-Squeeze-vs-Pump-vs-Gravity