UV water purifiers vs. water filters

Reverse osmosis systems, ultrafiltration systems, carbon filters, and ceramic filters all separate contaminants from water through tiny pores of a filter or a membrane. Unlike water filters, a UV water purifier does not remove particles from water. UV treatment purifies water by exposing living organisms to ultraviolet light, but it does not filter them out. Water filters do not remove bacteria and viruses as well as a UV system. UV disinfection works alongside water filtration systems to provide clean water.

Is UV necessary for a water filter?

UV purification is not necessary for a water filter, but a water filter is necessary prior to a UV system. UV systems are most effective when water is clear, so they must have at least a five-micron pre-filter to prevent living organisms from hiding behind loose particles. You could use a sediment filter to remove dirt and debris from a well water supply or a water softener to reduce iron as prefiltration. A UV purifier is the last thing water passes through on the way to the house.

Test your water quality before you use a UV system to make sure the water does not exceed these levels:

• Hardness < 7 gpg (grains per gallon)
• Iron < 0.3 ppm (parts per million)
• Manganese < 0.05 ppm
• Turbidity < 1 NTU (nephelometric turbidity units)
• UVT < 75%
• Tannins < 0.1 ppm