What you are actually treating
Las Vegas Valley water is technically safe to drink as it arrives from the curb. The Southern Nevada Water Authority treats Colorado River water from Lake Mead to EPA and NSF standards, and the water leaving the treatment plant meets every regulatory limit for contaminants. The case for a water softener in Las Vegas is not a safety case; it is a household economics and home maintenance case. The relevant water quality measure is hardness, expressed in parts per million of calcium and magnesium ions. Las Vegas Valley Water District supply consistently runs over 280 ppm, which places it among the hardest municipal water supplies in the country. For comparison, water in the 0 to 60 ppm range is considered soft and water above 180 ppm is considered very hard; we are well over even that. At our hardness levels, every drop of unsoftened water that evaporates anywhere in your home leaves a measurable mineral deposit behind. That is what causes the white crust on faucets, the chalky film on glass, the chronic scale inside water heaters and condensing gas tankless heat exchangers, and the early failure of dishwashers, washing machines, ice makers, and any other water-using appliance. None of this is dangerous. All of it is expensive over the course of a decade of ownership, and we want every customer to understand the difference clearly before they decide what they want to do about it.