Clean drinking water is an incredibly important consideration for any trip into the backcountry. If you’ve ever had the pleasure of experiencing a stomach parasite (we have, it’s awful), then you already know how critical clean drinking water is. If you haven’t, good! Let’s keep it that way.
For any extended trip into the wilderness you’ll want a treatment method for cleaning your drinking water. But when you start shopping for a good filter or purifier, you’ll quickly find that there are A LOT of different products out there.
We put together this guide to explain key treatment method differences and to share our personal favorite products. We’ve spent hundreds of hours researching and testing these tools, so we hope you find this information helpful.
Chlorine Dioxide Drops & Pills
WEIGHT: 2 oz
PROS: Ultralight, easy, affordable, kills viruses
CONS: Wait time necessary
We almost always backpack with chlorine dioxide water treatment. At very least, we carry it in pill form as a backup if our main filtration system malfunctions, clogs, breaks, or loses battery. We also often use it in drop form as our main treatment method because it’s affordable, easy to use, and nearly hassle free. We hardly notice any taste or smell with chlorine dioxide, but waiting time is required for it to work (see “wait time” section below). The drops are more affordable per liter, but you have to pre-mix them and wait 5 minutes before adding them to your water. The pills are more expensive, but they’re easier to use: just plop one into a liter of water and wait for it to work. When using chlorine dioxide as our main treatment method, we usually bring both pills and drops, then use whatever’s most convenient at the time.
WAIT TIME: In order for chlorine dioxide to be effective against cryptosporidium, a 4 hour wait time is required. Giardia, bacteria, and viruses are all killed in about 30 minutes, but crypto takes longer to kill. When we judge a backcountry water source to be clean (read “judge the source” section above), we normally wait 30 minutes after treating with chlorine dioxide before drinking. If we don’t trust the water source, we wait the full 4 hours. Obviously, this is a personal choice that’s up to you.