Part of the common marketing practice these days, the listing of the bacteria in the water that are destroyed by the action of the UV water purifiers clearly tells a buyer what to expect when buying such an item. Ultraviolet light is widely considered one of the most powerful disinfectants discovered so far, which would explain the extensive range of applications both in households and industry. What exactly happens in the UV water purifiers that the results are so remarkable? We should begin by saying that the density of micro-organisms in water very much depends on the source, the geographical area as well as the climate. UV water purifiers are low-energy devices that eliminate the bacteria by exposure to light. Micro-organisms are not literally destroyed, but inactivated. One of the properties of light is that of operating changes in the living structures, and this is the main working principle behind the efficiency of the UV water purifiers. The ultraviolets in the system have a specific wavelength and the water exposure time depends on the flow rate and the length of the lamp in the device. The water will absorb UV energy and the highest purification efficiency will always be closer to the ultraviolet source. In common UV water purifiers, the water will enter the inlet of the lamp and flow through a chamber where the germicidal lamp is located; afterwards, the purified water will leave the device through a nozzle in the outside chamber wall. Certain UV water purifiers can be adjusted so as to handle very high flow rates, up to 2400 gallons per hour; should you need a superior capacity, there is always the alternative of using multiple UV water purifiers connected in series or in parallel. Nevertheless for such complex combinations, professional maintenance is often required. When you have to choose from among several models of UV water purifiers, there are some features that will tell you which item is the right one for you. First of all, go for expandable systems if you know that some time later you will want to extend and change the parts. Then, try those designs that have only one lamp per chamber since they are considered a lot safer while enabling the user to securely monitor the system. Last but not least, the best UV water filters are those that have the lamp covered with a quartz protection so that the temperature doesn't drop when water passes through.