Water Purifier vs Water Filter vs Iodine in the Outdoors

Water purifier, water filter, iodine tablets, or chlorine... How do you decide? The simplest way to look at this:

• a water filter gets rid of protozoa and parasites, even bacteria, but it does not remove viruses.
• a water purifier eliminates all of these plus viruses. The Environmental Protection Agency (EPA) standards require water purifiers to eliminate 99.9% of all viruses. Chemical contaminants such as mercury, however, have no sure way to remove them. On the positive, hiking trails rarely are below areas where hazardous chemicals have been released. For backpacking in a foreign country, buying a water purifier could save your life. You just never know what might be in the water.
• Iodine tablets, chlorine or boiling water will kill viruses --however, each of these methods has its own disadvantages. Boiling water necessitates the use of a stove or fire, uses up fuel you likely need for cooking, and it takes up precious time which could be better spent enjoying the views, photographing your area, or taking a quick jaunt from your base camp. Iodine and chlorine add a smell and color to the water and leave a distasteful flavor that lingers in the mouth. Some folks are allergic to iodine, nor should it be used by pregnant women. Alone, neither iodine or chlorine will remove the parasite that causes cryptosporidiosis. Neither will tablets remove full of sediment and particles giving safe but dirty-looking water.

A water filter does not change the taste or color of the water and is easy to use. Most utilize a type of small pump mechanism similar to that of a bicycle pump. Some take more energy than others to pump the water through the filter. All require periodic cleaning. They can have plastic, ceramic or even metal internal parts. Plastic ones are the easiest to break, especially in cold temperatures. Take care not to drop a ceramic one because it will shatter. It will also add weight to your pack.

Considerations when buying a water filter: pore size, chemical treatment type, the average life of the filter, how much time it takes to filter one liter of water, how much weight it will add to your backpack, how easy it is to get replacement parts, and price (of both the filter itself and the replacement cartridges). Also, when comparison shopping take a look at reliability and endurance. You might be in the middle of nowhere and dependent on that little filter for your survival.

With each increase in water filtration system technology has come more and more products from which to choose. While ten years ago the technology in water filters could eliminate protozoan cysts and bacterial down to 1 micron, now they can eliminate them down to .02 microns. And, if you want to think of how small this is in another way, just consider that one human hair is 80-100 microns. The period at the end of a sentence is 500 microns.

MSR, Katadyn, Pur, General Ecology, Timberline, and Hydro-Photon, are among the most popular manufacturers of water filters and purifiers. The innovative Hydro-Photon Steripen water purifier was introduced in 2000 and was the first to use ultraviolet light to destroy viruses, bacteria, and protozoa, including giardia and cryptosporidiosis. It is battery-operated. Several companies now also manufacture water purifier tablets and drops made of stabilized chlorine dioxide. These get rid of contaminants and are easy to take with you. Water filters without pumps are also now readily available. These can connect to water bottles or hydration bladders, and can be used in any available container or in open water.