Once you break camp, a gravity water filter is the fastest way to purify water. Simply hang the dirty water bag high off the ground in a tree, and let the filtered water flow down to the other bag. For wilderness trips in the North America, any of these gravity filters will take out the nasty stuff—protozoa and bacteria. But to kill viruses when traveling internationally, you'll need to buy a different product that works as a purifier. Here are our three favorite filters for camping in North America.
The Best Gravity Water Filters: Sawyer Complete 2-Liter Water Filter
U.S. military supplier Sawyer designs its gravity-fed filter to last for a million gallons. With that kind of longevity, your family's trips will be covered for at least a few years. The 2-Liter model has a pore size of .1 micron compared to the .2 or .3 micron rating of its competitors, giving it a greater chance of catching smaller bacteria. On the downside, it’s 5 ounces heavier than its lightest peer.
Capacity: .5 gallons
Filter Pore Size: .1
Filter Life: Unlimited
Flow Rate: .5 gallons/minute
Weight: 16 ounces
The Best Gravity Water Filters: Platypus GravityWorks 2-Liter Water Filter
Compared to other filters on the market, the Platypus has an incredibly fast flow. It can filter 2 liters in only 1.5 minutes. And with a .2 micron filter, it can safely remove giardia, salmonella, and cryptosporidium. The filter comes in two versions: a 9.5 ounce model that attaches directly to your water bottle or an 11.5 ounce version that drains into a 2-liter Platy bottle.
Capacity: .5 gallon
Filter Pore Size: .2 microns
Filter Life: 400 gallons
Flow Rate: .4 gallons/minute
Weight: 9.5 ounces
The Best Gravity Water Filters: Katadyn Base Camp Water Filter
By far the largest in the group, the Base Camp starts with more than 2.5 gallons of dirty water. Though it’s a bit more bulky when carried, it doesn’t weigh more than the other units. It also lacks a lower bladder, so you'll need to put a kitchen pot at the end of the four-foot hose to catch the clean water. Some of our testers have reported that the Base Camp clogs more frequently than other units and the flow goes down to a trickle.
Capacity: 2.6 gallons
Filter Pore Size: .3 microns
Filter Life: 200 gallons
Flow Rate: .1 gallons/minute
Weight: 11 ounces
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