Gear Preview

SteriPEN Adventurer

highly effective*
best with low-sediment sources
3.6 oz !

SteriPEN's Adventurer water purification device offers an intriguing alternative to filters and chemicals. The 3.6 ounce SteriPen (batteries included) uses ultraviolet light to neutralize 99.99% of all bacteria, protozoa, and viruses, making this one of the more comprehensive killing machines on the market.

As the name implies, you use the Adventurer like a glowing pen to stir your water, allowing the unit's powerful UV light to nuke frolicking microorganisms. The whole process takes about 90 seconds per liter of water (the unit times itself to prevent you from cheating), making the SteriPen only slightly slower than pumping water via a traditional filter, and significantly faster than chemical treatments.

Compared to chemical treatments like Iodine tablets or Aquamira, the SteriPen is only modestly heavier, equally effective, and adds positively no funky taste or odor—in fact, it adds nothing to your water, making the SteriPen a highly attractive choice if you're concerned about chemical exposure.

Compared to most pump-and-filter units, the SteriPen is notable for its ability to kill viruses. International travelers especially will love this feature. Four-season backpackers and mountaineers will appreciate the freeze-proof design of the SteriPen, though you will need to be careful to keep the batteries warm enough to remain operational.

The SteriPen requires you to have a suitable container for purification purposes. Generally this means you'll need some sort of wide-mouth bottle, such as a one-liter HDPE Nalgene, for proper and thorough stirring. Hydration Bladders alone are not sufficient.

Note that the SteriPen's effectiveness (*) depends on the relative clarity of the water. If you need to purify water that contains a lot of sediment or other particulate matter (ie, vegetation, algae, etc.), you will need to pre-filter the water using a coffee filter or bandana, as sediment and particulates impede the ability of the UV light to evenly zap the water.

Available information suggests that when used properly with clear (not cloudy) water, the SteriPen is a highly reliable water purification system. While I haven't had the opportunity to use one myself in the field, the SteriPen's low weight and high efficiency do make it a quite appealing option.

Note: according to SteriPEN, you can expect to treat approximately 50-55 liters of water per set of batteries with the Adventurer. The larger, 5.4 ounce SteriPEN Classic will treat up to 100 liters of water before requiring new batteries.