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Steripen Prefilter Question
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Christopher Kuzak
Steripen Prefilter Question on 06/07/2011 22:36:56 MDT Print View

I've read up and down through all the Steripen threads, but I am stilling having some issues with using it. Briefly, I recently bought the pen to replace my Katadyn Hiker when I am in areas where water is fairly clear (Sierras) and I don't have to drink from cattle ponds (Henry Coe, etc.). The Hiker has been my reliable friend for a long time, especially since I'm not a chemical person. However, the recent REI sale got to me and I couldn't pass up the weight savings.

What I am struggling with is the prefiltering. I purchased a wide mouth 32 oz Naglene Canteen to use with the pen. I plan to decant to a platy if I need some additional liters for longer stretches (just using a cheap little funnel to decant). After looking at several coffee filter options, I gave up, cut a small square out of an old white t-shirt, and used a rubber band to fold it over the mouth of the canteen. It seems to work in my home tests, but I have yet to hit the trail with this setup.

Does anyone have any thoughts on what I am doing? Are there problems anyone sees with this method of prefiltering? Should I give up and go back to my tried and true Hiker?


Ken T.
(kthompson) - MLife

Locale: All up in there
Re: Steripen Prefilter Question on 06/07/2011 22:48:29 MDT Print View

If you are using it where you plan to, where the water is clear, you just want to filter out the floaties. Many hear use a bandana. I have a piece of nanoseeum with some elastic to fit my bottle. Some here use a diesel fuel prefilter too. Just depends on your comfort level. No need to lug the filter.

Mike W
(skopeo) - F

Locale: British Columbia
Steripen Prefilter Question on 06/08/2011 01:12:46 MDT Print View


Edited by skopeo on 06/16/2015 14:33:00 MDT.

Christopher Kuzak
Thanks on 06/08/2011 11:12:36 MDT Print View

Thanks for the advice. It's just the difficulties of adopting a new setup and figuring things out.

Nico .
(NickB) - MLife

Locale: Los Padres National Forest
prefilter on 06/08/2011 13:14:26 MDT Print View

+1 to the biodiesel 1-micron fuel filter. I've been using it with both my steripen (for solo trips) and gravity filter (for group trips) for the last few months. Seems to work well for most conditions at filtering out floaties, most dirt/suspended solids (but not quite all), etc.

If you're dealing with really clear water though, a bandana ought to do fine.

Stephen Barber
(grampa) - MLife

Locale: SoCal
Bandanna and Nalgene canteens on 06/08/2011 16:02:40 MDT Print View

Hiking primarily in the Sierras and other "clear" water areas, I too use a bandanna if any pre-filtering needs to be done. I have both a Steripen pre-filter and some bio-diesel bags, but have never felt the need to use them.

FWIW, I've found a 1 liter Nalgene "canteen" with the top cut off (ie, the heavy part) works great for using with the Steripen. I then pour the treated water into a light weight water bottle. The heavy duty plastic bag of a Nalgene canteen travels wrapped around the Steripen.

Just trying to keep things light!

Stephen B Elder Jr
(selder) - M

Locale: Front range CO
another +1 to the dudadiesel filter on 06/08/2011 16:25:53 MDT Print View

Flows water much much faster than a coffee filter, and if you ARE concerned about critters in the say 50 - 100 micron range that might be resistant to uV or chemicals, it should more predictably remove them then a bandana, used sock etc.

J. Lopes
(Jay_NJ) - F
coffee drip on 06/08/2011 16:42:18 MDT Print View

I use the gsi coffee drip filter.

It weighs more then I would like (1.4oz on my scale), but it is bullet proof and protects the threads of my widemouth nalgene canteen from contamination and keeps out the floaties,etc.. The steripen adventurer opti also conveniently fits inside it snugly for protection in the front of my pack for storage.

I have in the past used a bandanna, but I found in slow moving streams that it took forever to fill and I then had to wipe down the threads with my pack towel.

Randy Martin
(randalmartin) - F

Locale: Colorado
Re: prefilter on 06/08/2011 16:49:53 MDT Print View

So for those that use the dudadiesel filter. What size do you use and how much do they weigh? Looking on their website it looks like the #3 size is the smallest they offer. Also when you use them is it a situation where the water flows through somewhat slowly?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Steripen Prefilter Question on 06/08/2011 16:56:18 MDT Print View

If there are no large quantities of gunge in the water, why bother with a pre-filter at all? I don't carry one, and there have only been about 2 occasions in the last 20 years when I have bothered - then I used my handkerchief. Not worth the weight. I use my cooking pot for the sterilising.


Mike M
(mtwarden) - MLife

Locale: Montana
other thread linked on 06/08/2011 22:17:27 MDT Print View

little confused w/ the linked thread- it's describing using a steripen first, THEN pre-filtering into a bottle to drink

the only reason I would consider using a pre-filter is to insure the steripen will work optimally

I had planned on cutting down a 2 liter platy to use as my "sterilizing receptacle" :) would this diesel filter be larger enough to use w/ the end of a cut platy? could I simply hold it in the cut opening and then scoop my water? to what extent does it impede water from going in?

I'd like to continue to use 1 (and occasionally 1/2) liter platy bottles to carry my water



Mike W
(skopeo) - F

Locale: British Columbia
Steripen Prefilter Question on 06/09/2011 01:32:30 MDT Print View


Edited by skopeo on 06/16/2015 14:54:59 MDT.

John Jensen
(JohnJ) - F

Locale: Orange County, CA
DudaDiesel on 06/09/2011 04:47:28 MDT Print View

I notice that the media is available as 72" width, 36" Length sheets. That would be a big supply of pre/post filter.

They have a lot of micron choices, are you all finding smaller better, or would say 5 micron be good while providing better flow?

(update: I'm a new hiker but I think I'm tempted to follow the bandanna when needed advice, just because I'm not seeing "I used a steripen and got sick" stories.)

Edited by JohnJ on 06/09/2011 04:49:44 MDT.

John Jensen
(JohnJ) - F

Locale: Orange County, CA
got sick stories on 06/11/2011 08:03:05 MDT Print View

That was really an invitation for "I used a Steripen and got sick" stories, or "my friend did." Learning from failure and all that.

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: Steripen Prefilter Question on 06/11/2011 08:17:11 MDT Print View

The idea is that large particles can harbor and protect bugs from the UV. A bandana or microfiber towel will work for the big stuff. I made my own coffee filter holder from Seal-a-Meal material.


You can buy a commercially made one at

John Jensen
(JohnJ) - F

Locale: Orange County, CA
Re: Re: Steripen Prefilter Question on 06/11/2011 08:44:52 MDT Print View

Oh I get the idea Dale, but to really see the necessity (or at the detail, what micron level one should have for pre-filter), I think we'd need to see the boundary condition.

[metallic] Coffee filters have a much larger micron size than commercial pre-filters. Bandannas are larger than either. The "I rarely filter" reports are the most open-filter size ;-)

So ... if I search the web and all four groups say "I did X and didn't get sick" ... it's not really an endorsement of any particular practice.

Edited by JohnJ on 06/11/2011 08:46:41 MDT.