How to Use a Steripen to Treat Water

Have you heard about SteriPENs but don’t know how they work? In this video I show how I use my SteriPEN to treat water from streams and lakes when I’m backpacking.

Want to learn more about Water Treatment?
Hiking 101: Water Treatment
Gear Review: SteriPEN Classic
Gear Review: SteriPEN Adventurer Opti

Ask Hiking Lady: Does the SteriPEN pre-filter keep the Nalgene threads bacteria free?


  1. Hiking Lady says:

    Hi Ronald, it takes 2 CR123 batteries. It can roughly handle 100 treatments on a set of batteries. If you use the flashlight feature it would be less than that. Happy trails!

  2. Hiking Lady says:

    Yeah that makes sense! I end up loaning mine to friends whenever I’m not using it. ๐Ÿ™‚

  3. SoCal Hiker says:

    Thanks, Hiking Lady! I’m going to add it to my wish list, but down towards the bottom. I hate to spend money when I’ve already got something that works perfectly fine (albiet with more weight).

  4. Hiking Lady says:

    Great question! Yep, I’d consider switching because the Steripen is much smaller and lighter than a filter, including the Katadyn Pro filter.

    The Steripen Adventurer Opti weighs 3.6oz including batteries vs. 11oz for the Katadyn Pro.

    Using CR123 batteries you’d get 50 treatments (50 Liters) out of a set of batteries. So for 3 weeks on the trail, you’ll probably need 4-5 liters of water a day so about 84-105 Liters total. An extra set of batteries (which I always take even on short trips!) will be another 1.2oz. So even if you had 3 sets of batteries your total weight would be just 3.6oz + 2 sets of backup batteries at 1.2oz per pair = 6.0oz. Still a lot lighter than a filter! ๐Ÿ™‚

    Cost is about $100 + a few bucks for CR123 batteries.

    In case you didn’t see my reviews, here are my write-ups about the Steripen Adventurer Opti and the Steripen Classic. Have fun on the JMT!

  5. SoCal Hiker says:

    I’ve been happily using Katadyn water filter in the past. For my three week JMT trip this summer, should I consider switching? How much do these cost? How many liters can you treat on a battery charge?

  6. Hiking Lady says:

    @David: That’s right – no more nasty tasting water!

    @Carl: Yes, the light emitted by the Steripen is safe to look at. Steripens emit UV-C light, which cannot pass through containers, whether they’re glass, plastic, metal, etc.

  7. Hiking Lady says:

    Hi Paul, glad you found the videos! Yes, there is now a “Hiking Lady Channel” on YouTube. I plan to post more periodically. Some things are just better explained on video ๐Ÿ™‚
    Once I start doing trail reviews and such you’ll see more of me ๐Ÿ™‚

  8. Paul says:

    I’ve just noticed you started using Youtube ( I just found 2 videos)! I like it ! They are short, but straight to the point…
    Any time soon we’ll see “the whole you ” ?
    Still building my courage to get myself out there ( on Youtube that is )…

Comment or Question:

Your email address will not be published. Required fields are marked *