Ultraviolet distillation, nanofiltration, reverse osmosis and water treatment systems eliminate viruses from water. Ultrafiltration systems can also be moderately effective in removing viruses, depending on the pore size of the filter. In a nutshell, the main difference between a backpacker water filter and a water purifier lies in the level of protection these two treatment devices provide against harmful microorganisms that may lurk in field water sources. Generally speaking, a water filter is designed to eliminate protozoa and waterborne bacteria, but not viruses.
A water purifier is designed to eliminate protozoa, bacteria and viruses, offering a higher level of defense. As you can probably guess, nanofilters are the best for filtering viruses, bacteria, and protozoa. CDC rates nanofiltration as highly effective for all microorganisms. Membrane and depth filters are used to remove viruses from water.
Only RO and NF guarantee complete virus removal. A fraction of some of the smaller viruses (enteroviruses) and phages (F-specific phages and somatic coliphages of the Microviridae family, i.e., Øx17 with sizes around 25 nm) are only partially eliminated by the most commonly used ultrafilter membranes in the water industry. For every product sold, a child in need receives drinking water for a whole year. If you are traveling to less developed countries, where water treatment and sanitation infrastructures are poor, a water purifier is the safest option.
In distillation, water is heated to the boiling point and then water vapor is collected as it condenses and returns to a liquid state. That's why I rely on the results of third party lab tests on filters if I want to know how the filter works. With a filter pore size of approximately 0.0001 microns, reverse osmosis is even better than nanofiltration for filtering viruses. If they appear in a water test, it suggests that surface contamination has gotten into the water and that there may be microorganisms that cause disease.
This is because municipal water providers chlorinate water to kill bacteria, viruses, and other microorganisms. However, tasting or smelling chlorine in water is an indication that your water supply is being properly treated to detect microorganisms. The Premiere PS-2000S is a two-stage water filter system that has a sediment pre-filter and the same ultrafiltration membrane as the PS-1000 mentioned above. The amount of chlorine you use will depend on the presence of biofilm, the depth of your well, the pH of the water, the temperature of the water, etc.
Just because the water can be “safe” does not mean that the water has always been or will continue to be safe. Don't waste time or money changing filters every year, six months or more with other filter systems. Needless to say, it's important to make sure you have proper filtration to protect your home from viruses and bacteria in the water, and unfortunately, not all filters will work. The Premiere PS-2000PB is a two-stage water filter system that has the same ultrafiltration membrane as the PS-1000 (mentioned above) plus a special carbon post-filter for lead.
However, it's also an old-fashioned way of treating water: municipal water providers can and should do better. Municipal water providers often disinfect water with chlorine, which kills most waterborne pathogens, including those that can cause typhoid fever, dysentery, cholera, and Legionnaires' disease.