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Rated 4 out of 5 by from This works well unless it gets wet I found this so easy to use I almost swooned! However, after 3 days the battery case got wet and that was the end of my sterilized water. The directions do say to keep the pins dry but you apparently have to be more careful of moisture than I was. Note that it was raining, that complicated the matter. So I recommend it but with the note that you better take a backup.
Date published: 2014-08-23
Rated 5 out of 5 by from Stop Water Bottle Waste I have had the same Steripen for the last 7years, and it goes with me whenever I travel outside of the U.S. or just into the backwoods. I am very happy to say that I have not fallen ill while using it either, and it has been put the test in Nepal, East Africa, and Mexico. When I have friends tell me they are going abroad I tell them this is the one thing they have to buy! Stop plastic waste and drink the water.
Date published: 2015-04-07
Rated 5 out of 5 by from Solid solution Have an earlier version of the Steripen and like it a lot PRO: + FAST: your water is ready in a minute + COMFORTABLE: you can purify the water at your cooksite or other location - no more balancing on the bank of a stream while you pump + DURABLE: no moving parts CON/ Considerations: - ELECTRIC: producing UV light with sufficient intensity to scramble microbe DNA requires a lot of "juice". I find I'm okay with fresh lithium AA batteries for several days (haven't tapped them out), but if you go alkaline, you'll need replacements. With NiMH you'll need a solar cell or other means to recharge. - UNREPAIRABLE in the bush: In theory, the glass lamp is delicate and could be cracked/ruined, but it's capped when not in use so it doesn't seem to me to be much of an exposure. I travel with a small amount of Iodine and asorbic acid (to knock out the metallic Iiodine taste after it has done it's job) as a failsafe. - VOLUME: You can treat a liter at a time. Some gravity-driven or squeeze-pressure driven systems can hold larger volumes of untreated water, but Steripen also works very quickly, so 1 liter in a minute still beats pump-action solutions. You SHOULD have a spare "dirty" water vessel (like a disposible gatorade bottle) for fetching water to pour into your bottle to treat if you want to be totally sure you don't have any untreated water on the rim/threads of your bottle.
Date published: 2014-05-31
Rated 5 out of 5 by from Best water purifying solution Fantastic product, easily the best I've used for it's purpose. The battery life has greatly exceeded my expectations (I use commonly found rechargeable NiMH). Both the pen and filter are simple to use, quick, and reliable with a wide mouth water bottle.
Date published: 2014-07-30
Rated 5 out of 5 by from Easy and light I have quite a bit of experience with pump and filter systems, and definitely prefer this device. It's light and much simpler and easier to use than systems with a lot of tubes and filters and pumping into some reservoir. I use only in very clear mountain water. I would be less confident with more turbid water supplies.
Date published: 2014-07-25
Rated 4 out of 5 by from Do you trust your batteries? I just got this, for an overnight backpacking trip (2 people). When they say to use quality batteries + have backup, they're not joking :) Mine were Toys R Us (not *from* TRU but *branded*) and, to be honest, they were only *almost* new (used for a couple of hrs in a lamp). I thought they'd do for such a short trip. Anyway, after only about 64oz (about 2L), the thing quit on me. I have since replaced the batteries and have done several treatments (about 18L in 1L and 1/2L increments) just to make sure it was the batteries. My plan was to keep going until the new batteries (Duracell) ran out but they didn't (I got bored). Otherwise, no serious problems. When using the wide mouth bottle adaptor (very handy), I blow on it before turning the bottle upside down to shake. This removes excess water; otherwise it drips down the pen towards the bottom. The battery compartment seems well protected (with a rubber gasket) but you never know. Also, jam the pen in pretty tight or it leaks as you shake. So I think this device is great as long as you can count on your batteries. Otherwise I'd give 5 stars.
Date published: 2015-04-17
Rated 1 out of 5 by from Not reliable I just took this filter on it's second backpack trip, the first trip it worked fine. I was in Bruce Peninsula, CA and we were surrounded by water so there was no need to carry in water since I had this filter. Nothing makes you panic faster than realizing your water filter is not working. The green button flashed as though it worked but the UV light wouldn't turn on. When it did turn on it shut off after 10 seconds. I changed the batteries and had to click the button about 10 times before the UV light finally came on and it seemed to work okay then. I tried a second bottle and the pre-filter was quickly clogged and needed to be rinsed a lot and I was uneasy about it really filtering safely. Then I was never able to get the UV light to come back on. It appeared that there may be a little bit of water that got into the light section. I am so disappointed in a water filter that got ruined on it's second trip by water! I am returning this and getting a tried and true charcoal filter. Please bring a back up to filter your water if you choose to buy this.
Date published: 2015-06-15
Rated 4 out of 5 by from SteriPen Classic 3 Reliable in clear water, easy to use, batteries are available most places, not the lightest with 4 AA's.
Date published: 2016-01-09
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Questions & Answers

What's the difference between Steripen Classic and Classic 3?  What does the LED window show?

Asked by: Dan the Birder
The biggest difference between the older model, Classic, and the Classic 3 is the number of liters you can treat with a set of batteries. Classic 3 has improved circuitry which allows effective use of alkaline batteries. With the Classic, only lithium batteries were recommended. With Classic 3 you can treat about 50 liters using alkaline or 150 liters using lithium. Other improvements were added - like the cap is easier to remove and the casing is more watertight. The LED indicators tell you the status of the treatment and the batteries and warn you when you have 100 treatments left (out of 8,000 treatments provided). If you register it at, they'll give you a new SteriPEN if you use all 8,000 treatments.
Answered by: J M
Date published: 2018-02-11

Looking into bike-packing, would this work for multi-day and extended trips?

Asked by: Dancinghiker
Many of bikepackers choose SteriPEN for their water purification needs because of its small size, ease of use, and fast operation. If you check out packing lists online, it's the choice they are including in their packs. SteriPEN was also recently featured in a packing list in Bikepackers Magazine. 
Answered by: SteriPEN
Date published: 2018-02-11

Can one use a SteriPen to safely sanitize a water bladder?

Asked by: jacquelineandtyler
When I travelled in South America through Quito, Peru and Chili, I used the USB rechargeable version of Steripen, and supplied water for 4 people for two months using a platypus 3 liter bladder. No-one got sick from it. It was clear, pre filtered water, and I'd run the Steripen twice while occasional swirling the water, attempting to ensure all of the water was exposedto the light. Worked great for me in this way.
Answered by: Benevolent Wind
Date published: 2017-02-10

I am going to be traveling to Mexico. I have a sore spot for "aguas" which are different flavored juice type drinks that are sold by venders. Would the steripen work for this type of drink or any drink that is more than water?

Asked by: Mlowe
​This purifier is designed to work only on water.
Answered by: REIservice
Date published: 2017-03-07

I'm traveling to kampala, Uganda could this be used and trusted? 

Asked by: Emilie
​This item is best used for tap water in lesser developed countries. For more information regarding specific countries, please contact the vendor.
Answered by: REIservice
Date published: 2018-02-11

I use contigo metal drink container, can I use a sterile classic 3 in them to purify the water? Or do I have to worry about damage to my container? Thank you

Asked by: Mousseybaby
​The water purifier will not damage your water container.
Answered by: REIservice
Date published: 2017-06-02

Does the Classic SteriPEN neutralize Leptospirosis ?

Asked by: Kanaka
​Yes, this will neutralize Leptospirosis.
Answered by: REIservice
Date published: 2018-02-11

How many batteries does it take? In other words, how many in a set? If it can use AA or AAA size, how many of each? I don't think the specs state.

Asked by: Peter on the Trail
The Classic SteriPEN requires 4 AA batteries to operate.
Answered by: REIservice
Date published: 2018-02-11
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