With each liter of water weighing 2.2 pounds, I’m a big fan of leveraging water sources near my campsite or hiking route rather than carrying unnecessary weight. After trying multiple treatment options over the years, I find the Katadyn SteriPEN Ultra to be the easiest, fastest, and most reliable method. All you have to do is fill a bottle, click a button, insert the UV lamp into the water, stir, and then wait for the LED screen to confirm that the process is complete. For me, this is way better than pumping, waiting on a gravity-fed system, or tasting iodine.

While Katadyn sells a variety of SteriPEN UV filter models, I’ve settled on the SteriPEN Ultra for several reasons.

I love the rechargeable battery and micro-USB charging port, especially since I already carry a small battery pack to keep my phone charged for offline maps and GPS use.

I also find the Ultra‘s LCD screen to be much easier to use than the somewhat cryptic red/green indicators on other models. When you first turn it on by clicking once for 1 Liter or twice for 0.5 Liter, the screen immediately confirms the selection made so that you don’t accidentally undertreat your water.

After inserting into your water, the screen displays a countdown of how many seconds are remaining until treatment is complete.

If you accidentally remove the lamp and sensors from the water, you get an obvious warning of incomplete treatment.

The screen will eventually show a confirmation of completion while also displaying the remaining battery and lamp life for proper planning throughout your trip. With other SteriPEN models, you’re just guessing as to how long your bulb and batteries will last you.

One other thing I love about the Ultra is that it fits inside of a wide variety of water bottle sizes. Here I’ve inserted the bulb into a typical 12 oz disposable water bottle before turning everything upside down to shake and agitate the water for treatment. The soft and tapered surface fits a variety of water bottle sizes while maintaining a tight seal to prevent leakage. Other models like the SteriPEN Adventurer simply can’t do this!

In the image above, I am simply filling a Nalgene bottle from a stream before applying the UV light sterilization. However, this sometimes leaves bugs, dirt, and other particles in the water. If desired, you can also pre-filter.

The SteriPEN Water Bottle Pre-Filter screws directly onto a Nalgene or comparable wide-mouth bottle and features a screen aperture of 17 square microns. You can alternatively use a shirt, coffee filter, or even pantyhose stretched over the bottle opening. Or, you can just enjoy the added texture of nature’s water!

I do still carry a set of iodine tablets in my first aid kit as a backup in case I lose or break the SteriPEN, but thankfully it has never failed me.