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SteriPEN review

A review of UV Water Sterilization using the SteriPEN Journey

Collecting water from a nearby river, stream or spring can often mean the water is contaminated with a host of bacteria, parasites and other organisms resulting from animal waste or decay.  Fortunately, sterilizing water using ultraviolet (UV) light is quick, easy, and works without the use of any chemicals.  This portable UV sterilizing device is perfect for treating water while backpacking or foreign travel.

Sterilizing 1L of water with the Steripen Journey

How does it work?

The SteriPEN (manufactured by Hydro-Photon) is equipped with an optical grade quartz lamp which emits a short wave germicidal ultraviolet (UV) light to sterilize waterborne pathogens – including Giardia and Cryptosporidium –  in 90 seconds. According to Hydro-Photon, “UV purification works as the ultraviolet energy emitted by the light is absorbed by the cells of the microbe, preventing cell enzymes from ‘reading’ its DNA.”  In other words, the DNA of harmful microorganisms that make you sick are not able to reproduce.

The UV process destroys the reproduction cycle of over 99.9 percent of harmful microbes – including viruses, bacteria, and protozoan cysts.  This device will not remove chemical toxins such as industrial runoff that may be present in the water.

The device uses a Liquid Crystal Display (LCD) displaying facial expressions to indicate a success or failure.  It is powered by two Lithium CR123 batteries and weighs 5.4 ounces (with plastic lamp case and batteries).

What containers does it work with?

The SteriPEN can be used to treat water contained within plastic, metal, ceramic, or glass containers. The SteriPEN can be used to treat water inside of a hydration bladder, but is not recommended. This is because you must take extra precaution to make sure the untreated water does not enter into the bite tube. Also, the bladder capacity often exceeds 1L and does not contain visible measure indicators, so you must be extra careful not to pour over the 1L limit. Therefore, it is best to treat the water within a separate measurable container, then pour batches of the treated water into the hydration bladder.

Is the UV light harmful?

The UV lamp is made of optical grade quartz, one of the few materials that is transparent to UV. The UV is not harmful to the skin because the UV is blocked by the plastic container. The visible light given off by SteriPEN is blue light – not ultra violet – and it is not dangerous to look at.

Operating Instructions

  1. Press On/Off button to turn the unit on.
  2. Select the amount of water to treat; 1 L is the default (max) and .5L is the second option (select by pushing on/off button a 2nd time).
  3. Immerse the bulb into the water and stir wand to agitate the water to insure a uniform amount of water is exposed to the UV.
  4. Timer will being a countdown to show when sterilization cycle is complete; 90 seconds for 1 liter (32 oz) or 48 seconds for .5L
  5. Water sterilization will indicate success (smiley face) or failure (sad face).  If there is a sad face, it is likely that the water is murky or contains solid particulates, and the UV light can’t effectively penetrate the water to sterilize it.  There is also a battery status indicator.  If the battery is low it will indicate a frown within the battery icon.


1. Reliable – 3rd year in operation – as of Feb 2011. 1. Requires treating in batches. Maximum of 1 L water treatment at a time.
2. Easy to Use – uses facial expressions to indicate
sterilization status, battery status.
2. Water treatment container must have wide enough opening and depth to immerse the UV lamp inside; The wand must be completely immersed in the water and have clearance for agitation to function.
3. Light Weight – 5.4 ounces (with plastic lamp case and batteries). 3. Relies on batteries. Necessitates carrying a spare pair.
4. No Chemicals – does not affect the taste of the water. 4. Murky Water Impacts – the unit may not function properly if the water is cloudy or contains too many
particulates.In this case, physically filter the water first (bandanna, paper coffee filter, or other means). May require a second UV treatment.
5. No Pumping – can be a con if you only have access to shallow water. See tips below. 5. Cold Weather Impacts: uses batteries & LCD making it sensitive to outside temperature; may not function if outside temperature is below freezing; may require warming up batteries/unit with hand; can not be used if water contains ice. Remove ice or allow it to melt first.
6. Effective – Inactivates 99.9% of viruses, bacteria, and protozoa.
7. Quick – 90 seconds to treat 1L of water


  • Keep separate water containers for treated and untreated water. Our untreated water container is a 6L platypus which we fill directly at the water source and carry back to our campsite to treat in 1L batches.
  • Don’t treat your water at the water source. Carry the platy (or untreated container) to your campsite and treat in 1L increments as you need it.  We always keep two separate 1L nalgene bottles of treated water available for cooking & drinking.  We also use these to fill up our hydration bladders.
  • Wipe off untreated water: The SteriPEN does not purify the threads or lip of a water bottle.  Make sure to wipe off any excess water from the threads of the bottle before drinking.
  • Battery longevity: The manufacture claims that a single set of disposable CR123 batteries will charge 50L of water between uses.  This statement seems to be fairly accurate.  If you use disposable or solar charged batteries, you will not get this many uses. Rechargeables will only last about half of the life of disposables and seem to result in more issues. Using disposables are recommended for this unit. Carry a spare pair with you!  The manufacture also makes a solar powered charging device to use with the unit, but we can not comment on it’s effectiveness since we don’t own it.
  • Water collecting in shallow pools: SteriPEN is a water treatement device not a water collection device.  If you are hiking in drought areas or need to collect water from shallow pool you should take a traditional pump system which siphons water.  We have used plastic zip bags to collect water from difficult to reach places. We lay the bag horizontally and fan the water inside; This takes patience.

Additional Details about the use of the SteriPEN can be found within the manual Download SteriPEN manual.

Additional Details about the use of the SteriPEN within the Hydration Bladder.


Collecting water from a shallow stream using a ziplock bag

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