Pocket Sized Water Purifier!

SteriPEN Freedom
SteriPEN Freedom
When you’re hiking in the wilderness, come across a stream, and need to refill your water, what do you do? There are several treatment options: filtering, boiling, chemicals, and my personal favorite, UV light! That’s how water municipalities do it, so why not just do what the pros do?

The SteriPEN company has a wide range of UV “pens”. I first bought my SteriPEN Classic a few years ago, and since then, it has been upgraded to a SteriPEN Adventurer Opti.

How SteriPENs work?

All SteriPEN models operate the same way. You remove the lamp cover, then immerse it in the water (you’ve got to collect water from a stream if you’re hiking in the wilderness and get it into a bottle), then stir the SteriPEN in the water until the LED light turns green. The UV light kills 99.9999% of bacteria, 99.99% of viruses, and 99.9% of giardia and cryptosporidium.

SteriPEN has a new product called the SteriPEN Freedom, the smallest of all SteriPENs – it can fit right into your pocket! Unlike the other models, this one can be recharged. The catch? It has to be plugged in to a USB slot…so your laptop, or a wall outlet if you slip on the adapter. For those of you who travel abroad and are likely carrying a laptop with you or a wall charger (and the appropriate international converter), this handy little model is the way to go. Slip it into your purse or pocket, and it can be used to zap bacteria and viruses from your drinking water.

SteriPEN Freedom charging
SteriPEN Freedom charging

For hardcore backcountry hikers, the SteriPEN Adventurer Opti is still my favorite. I just bring along a spare set of batteries ๐Ÿ™‚

Related Hiking Lady articles:

Hiking 101: Water Treatment
SteriPEN Adventurer Opti Put to the Test
How to Use a SteriPEN Pre-Filter

Happy trails!


  1. Hiking Lady says:

    Great question!

    There is a “SteriPEN Pre-Filter” that you can attach to your water bottle to help filter out sediment. Here’s a quick video on the Hiking Lady website about it: https://hikinglady.com/the-gear/how-to/how-to-use-a-steripen-pre-filter-in-the-wilderness/

    Also this page is helpful: https://hikinglady.com/reviews/gear-reviews/a-convenient-highly-effective-water-treatment-system/

    If you don’t want to buy a pre-filter, you can use a bandana or coffee filter on top of your water bottle to help get rid of fine sediment. The drawback is that the threads on the top of the bottle will touch the “contaminated” stream water (the pre-filter seals it completely so you don’t have to worry about it).

    Have fun hiking!

  2. Ansley says:

    I found your web site super helpful but I have beginner question. I
    like the idea of using the SteriPEN Adventurer Opti. My question is
    should you also use a filter of some kind to get rid of fine sediment
    and such?
    Thanks much,

  3. Hiking Lady says:

    Thanks for the comment. Ideally, the best water source in the backcountry is a moving stream. The worst option is stagnant water. If you do have to resort to getting water with sediment, I highly recommend using the SteriPEN pre-filter or else use a bandanna to strain out as much sediment as possible before filtering. Happy trails!

  4. Hiker Hiking says:

    So i’ve been using a pump-style filter for my whole life, but I feel like it’s time to join many other hikers a get a steripen. I hear that as long as you get it from a decent source (ie. no sediment) then the water will be fine.

  5. Stu says:

    Thanks for the review. I was a bit dubious about the effectiveness of these UV systems, but I have just bought the Steripen Journey after reading several reviews. Can’t wait to try it out…

  6. Hiking Lady says:

    Question I’ve gotten – how much does it cost. It’s $120 in the U.S. Not cheap, but definitely a high tech useful piece of equipment.

  7. Hiking Lady says:

    Thanks for the feedback, Trail Walker. One thing I keep in my first aid kit are iodine tablets…just in case. I much prefer using a SteriPEN, with my second choice being a pump…but when those options aren’t available, it is nice knowing I’ll still be able to have safe water by using iodine.

  8. Trail Walker says:

    Thank you Hiking Lady! I have been caught without drinking water and now need to purchase one of the SteriPEN purifiers.
    Continue to keep us apprised of the equipment out there!

    Happy Trails to you.

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