Despite its cool, clear refreshing look, most water available in the backwoods today is not safe to drink unless treated. Various chemicals, bacteria, viruses and plain old mud can turn a simple thirst quencher into gut-wrenching time a few days later as the bugs make their way thru you.
Boiling water kills bacteria and viruses, but doesn't get rid of sediments or chemicals, and is inconvenient when on the trail. Filters remove most bacteria and sediments, but not all viruses. Iodine and chlorine have their own pros and cons too when used as standalone treatments.
However, if you are only going to use one treatment tool - at least in North America - renting a good quality, hand-pump filter is the best solution. Common trail wisdom says that a filter is all you need because viruses aren't the problem here in the States; bacteria are, and filters will catch most bacteria. The argument continues that viruses are only a significant problem in other countries - the infamous Montezuma's Revenge, for instance, that is encountered south of the border. I've never gotten sick drinking water that was only filtered, and not further treated.
We rent a couple of different models, from Katadyn and MSR. Both are very popular and well reviewed, and very reliable out in the field. They have few mechanical parts that can go wrong at the wrong time. You'll get good pump volume without a lot of pumping effort, for about 12 ounces added to your pack. Or go with the group filter option that uses gravity to pull the water through the filter, from a "dirty" container into a clean one. If you have a large group, the gravity filters may be more efficient, and many solo backpackers take them out as well due to the convenience. Either approach, our low rental rate is quite frankly a small price to pay to avoid praying to the porcelain gods upon your return. an alterntive to renting, but with similar protections is a purchase item at about the same cost as a rental, with some pros and cons - the Lifestraw water filter.
You should also throw in some coffee filters to add to the input side to extend the filter life and function while you're in the field. The coffee filter is a cheapie add-on that catches the big stuff before it makes its way to the filter core. Unless you are planning on providing water for an entire marching regiment with just one filter, you won't have to worry about filter clogging on your trip. We clean and rinse out the filters after every rental.
Water filters help eliminate the biggie problems like Giardia and Cryptosporidium, which cause most hiker illnesses. However, these filters we rent do not eliminate viruses. While viruses are statistically less of a problem, if you want more protection, buy some of our treatment tablets to add to the water after you've run it thru the filter.
Here are some other common-sense tips for using the water filter you rent from us. Avoid filtering water in area where animal or human activity is obvious. As in, watch for horse crap at water sources along multi-use trails. Pump upstream from busy stream crossings. Avoid the temptation to filter from what appears to be clear rushing water. Instead, filter from still, clear water sources. Many microorganisms tend to sink to the bottom of still water while a rushing stream keeps them suspended. Alternatively, rather than filter directly from the trail source, put water in a trail bucket and filter from that. This gives you a chance to see how the water looks before you send it through your filter. If the water is cloudy, let it sit for an hour or so, then pump from the clearest water off the top. Don't save the first few streams of output from your filter; let a few go thru first to clear out any old water in the line. When you clean or handle any part of the filter, recognize you are handling a potentially contaminated object. Don't handle food or put your hands to your mouth after cleaning your filter. Avoid letting the input hose and output hoses touch each other so the output end that will go into your water container isn't contaminated.
If there are several hikers in your party, not everyone needs a filter. We suggest renting one pump filter for every two or three hikers. You could in theory handle lots more hikers than that, but after 3 or 4 people sharing, having a backup becomes a smart idea, and using just one pump for a lot of hikers starts to take a lot of time. Also consider the gravity filters we carry.
The filters are easy to use, but if you need a manual after it arrives, find those here for the Katadyn Pur Hiker, or the MSR Sweetwater. One last note - if we send you the Sweetwater model, we usually send along a wire brush cleaner along with it. It probably won't be needed at all, but if so, just a brief whisk in and out is all you need. Otherwise excessive brushing will ruin the filter cartridge, and you won't be happy with that.
Read from our article data base for more information on hydration and water treatment options.