Water treatment buying guide

You and your troop have been hiking half the day to reach the mountain’s summit. You’re thirsty — and even though your leader warned everyone not to eat snow, you can’t resist. So you reach down and pack a big white ball of snow. Looks clean, you think. And you start chomping.

Fast-forward 18 hours: The rest of your troop is out playing while you’re sitting on the toilet—been there all morning with some wicked diarrhea courtesy of that snowball you ate yesterday. Not fun.

Whether it’s snow or a clear mountain stream, you can get very sick from drinking untreated water.

“Even if it looks clear and clean, you’ve just got to do whatever you can to purify it,” says Jordan Romero, 13, who is on track to be the youngest mountaineer to summit all of the world’s seven tallest peaks. Luckily there are many ways to purify your water and several great gear options that make the job easier.

BOILING

This one is simple. Just heat any suspect water to a roiling boil. When half-inch-wide bubbles are rising from the bottom of the pot for about a minute, you’re good to go. “We always collect snow, melt it and boil it,” Jordan says.

Pros: Cheap, simple, very effective.

Cons: Slow, especially at high altitudes; can use lots of stove fuel; won’t remove silt.

CHEMICALS

Just plop in iodine or chlorine tablets or drops, and wait as they kill the nasties. Tablets cost between $10 and $15 for a pack of 20.

Pros: Ultralight, simple, great as a backup purifying method. “It’s quick and cheap,” Jordan says.

Cons: “It can affect the water’s taste,” Jordan adds. You need to wait 15 to 60 minutes before drinking, it won’t clean out the silt, and not all chemical purifiers are effective against all germs and things—be sure to check the label.

UV LIGHT

These battery-powered wands emit ultraviolet light to purify your water. Just turn one on and wave it around in your water. UV purifiers cost $100 or more.

Pros: Very portable, fast, easy, no chemical taste.

Cons: Won’t work in muddy water, requires batteries, expensive, can treat only small batches at a time.

MIOX

This stands for MIxed OXidant treatment. Basically it uses salt and electricity to make a water solution that interacts with your untreated water.

Pros: Easy, very portable.

Cons: Expensive, must wait for at least 15 minutes while water is treated, won’t filter out silt, requires batteries.

FILTERS AND MECHANICAL PURIFIERS

Filters use a handheld pump that pushes water through a tight screen and a filter that strains out germs as well as silt and such. These are good for wilderness areas where human virus contamination isn’t an issue. Purifiers go one step further (using iodine or electrostatic functions) to deactivate dangerous viruses. Purifiers are essential when traveling in areas where human waste might be contaminating your water source. These generally cost between $40 and $200. Look for one with a filter pore size of 0.2 microns or less. Also pay attention to its advertised liters/per minute, as this will tell you how long it will take you to pump the water.

Pros: Easy, removes chunky stuff and contaminants from the water, generally durable.

Cons: “They can be bulky to fit in your pack,” Jordan says. Also, they can be expensive and could clog and fail in the field.

HOW MUCH WATER DO I NEED?

A good rule: 2 to 3 liters of water per Scout per day. Don’t wait until you’re thirsty to drink. Always have it at the ready and drink small amounts frequently.

WHAT IF IT’S MUDDY?

Muddy water? No problem. Just let it settle in the bottom of a wide pot. Then very carefully scoop the clear water from the top. Next, strain it through a bandana or a paper coffee filter. Finally, filter, boil or purify and drink up!