Katadyn Steripen Ultra Water Purifier Review

Bottom Line

Each generation of the Steripen Ultra has led to improved design and functionality. In our experience, the Ultra has been a reliable and convenient treatment system. This UV pen is easy to use, works fast, kills all the bad stuff (protozoa, bacteria, and viruses), and best of all, it doesn’t require any pumping, squeezing, backflushing, or chemicals. Like all backcountry gear, there are downsides to the Steripen Ultra, but on the whole, we think it’s an excellent option, and that is why it is on our list of the best backcountry water purification systems.

Quick Specs

Water Quality

The Ultra uses ultraviolet (UV-C) light rays to safely purify clear water. The UV rays destroy 99.99% of protozoa (including Giardia and Cryptosporidia), bacteria, and even viruses. The downside with UV purification is that it won’t work with murky, sediment-laden water. Most pump/squeeze filters quickly clog in those conditions as well, so this isn’t a complete tradeoff. With a little planning and research, you can determine if the water sources will be generally clear enough for the Ultra. If you are forced to drink from an unideal source, you can always strain out particles or use a chemical tablet for certainty. If you commonly expect to purify water from murky sources (mud puddles, animal pastures, etc.) and you want to avoid chemical treatments, you may be looking for a filter beast like the MSR Guardian.

Ease of Use

Ease of use is one of the Ultra’s key strength and the main reason it’s won us over. With a standard small-mouth 1-liter water bottle, the Steripen is one of the most convenient and hassle-free water purifiers we’ve used.

The Steripen is 7.3 x 1.65 x 1.3 inches or about one inch longer than a standard pen and about as wide as a golf ball at its thickest part. It easily stashes away in a side pocket or front mesh pouch for quick access.

Treatment Time

The Ultra has a straightforward display that works well. Simple symbols display the unit’s battery life, lamp life, liter settings, a countdown timer, a smiley face when the water’s ready to drink, or a frowny face if something goes wrong. The display will be upside down while purifying with the plastic bottle method, but it’s still easy to read.

It takes 90 seconds to treat 1 liter and 48 seconds to treat a half liter.

Weight

The pen weighed in at 5 ounces (4.7 oz on our scale). The Ultra is light enough to take on any backcountry trip, including thru-hikes. It isn’t quite as light as the Sawyer Squeeze, but the minimal weight difference is well worth the upgrade in convenience. In addition, the Ultra weighs less than half as much as popular pump filters. Water purification chemicals are the lightest option, but you’ll have to wait 30 minutes before drinking. It’s all a matter of personal preference, but we like to use chemical treatments as a last resort whenever possible.

Most backpackers bring a small power bank on longer backpacking trips for GPS phone navigation, photos, and charging headlamps. If necessary, a power bank will recharge the Ultra while in the backcountry. Finally, we always recommend bringing backup purification pills just in case we have an equipment malfunction or encounter a truly gross/murky water source. This adds to the overall weight of the system, but backup purification and a power brick are generally always on longer trips.

Maintenance & Longevity

The Ultra comes with a built-in rechargeable 2200 mAh li-ion polymer battery that can be recharged from any USB power source. This means you won’t have to worry about replacing expensive, heavy, and hard-to-find batteries like previous models.

The Ultra will purify 50 liters on a full charge, which works out to roughly a 10-day water supply for one person or 5 day supply for two (4-6 liters per day, depending on conditions). That daily estimate is based on our personal experience and is a little conservative (we’ve purified well over 50 liters on a single charge). We initially didn’t like the feeling of having our water treatment method tied to a battery, but over time, the Ultra gained our trust.

The Ultra feels very sturdy and lasts for a long time, even in tough conditions. It has a hard case that covers the bulb and a soft case that protects the entire unit. The bulb is glass, so be careful not to drop it when it is unsheathed. If you’re rough on your gear, like to chuck your pack down couloirs or have butter-fingers, the glass bulb might not last as long as other water treatment systems.

The bulb in the Ultra is rated to work up to 8,000 treatments before it burns out. At 4-6L per day, that’s the equivalent of 4.4 years of clean water for one person. Also, if you use up your Ultra bulb, Steripen will replace it for free.

Should You Buy the Steripen Ultra?

We mainly like the Steripen Ultra because of its convenience compared to other purifying methods. With the Ultra, you no longer have to awkwardly crouch over streams and tire out your forearms pumping water. It’s also nice to avoid squeezing cold bags/bottles to filter water, which tires and chills your hands and fingers. Instead, this option is a hassle-free purifier that provides clean, safe drinking water in 90 seconds with minimal effort. While the Ultra isn’t the lightest or cheapest purifier on the market, its considerable strengths make it our go-to choice for water purification.

Cost is one of the Steripen Ultra’s biggest downsides. Though much cheaper than the best pump filter (MSR Guardian), the Ultra is twice as expensive as the popular Sawyer Squeeze. That said, Ultra’s convenience makes it well worth the price, especially if you plan to use it for many years.