Carbon vs. Reverse Osmosis vs. Pitcher Filters

The short answer

Short answer: A pitcher filter is the cheapest way to improve chlorine taste and odor in a few glasses at a time. An under-sink or whole-house carbon filter does the same job with more capacity and less hassle. Reverse osmosis (RO) is the only one of the three that reduces total dissolved solids (TDS), the minerals that make Las Vegas water taste hard. If you want lead or PFAS reduction, the type matters less than the certification on the label.

The Las Vegas Valley Water District puts it plainly: an inexpensive activated carbon filter, like those in carafes, can improve taste and odor, but it does not remove hardness, minerals, sodium or fluoride. Here is how the three options compare.

What the NSF/ANSI standards tell you

Packaging claims vary, so look for third-party certification. NSF explains the main drinking water treatment standards, and it also cautions that certification does not mean a product reduces every possible contaminant. Check that the specific contaminant you care about is listed.

• NSF/ANSI 42: Aesthetic effects such as chlorine, taste and odor. It applies to pitchers, under-sink units and whole-house systems.
• NSF/ANSI 53: Contaminants with health effects. For lead, EPA’s consumer tool says pitcher and point-of-use filters should be certified to reduce lead to 5 ppb or less under NSF/ANSI 53 and 42.
• NSF/ANSI 58: Reverse osmosis systems. TDS reduction is the required claim, and products can add optional claims such as lead, arsenic, nitrate and fluoride.
• NSF/ANSI 401: Reduction of one or more of 15 emerging contaminants, such as certain pharmaceuticals and chemicals not yet regulated.
• PFAS: EPA advises looking for NSF/ANSI 53 or 58 with PFAS reduction listed. As of April 2024, EPA says certifications mainly cover PFOA and PFOS.

Las Vegas tap water: what you are actually filtering

About 90% of Southern Nevada’s water comes from Lake Mead. LVVWD adds chlorine as water leaves its treatment facilities, which is the taste many people notice. A carbon pitcher or under-sink filter handles that well. See our post on why Las Vegas tap water tastes like chlorine.

The bigger local issue is minerals. LVVWD reports hardness of about 280 to 291 ppm, or 16 to 17 grains per gallon. Carbon does not touch that, so carbon-filtered water still carries the same dissolved minerals. RO is the option that lowers them at the drinking tap. Our post on TDS in Las Vegas tap water explains what that number means. For fluoride, LVVWD notes that some home systems reduce it and suggests asking the manufacturer.

Keep in mind that none of these drinking water filters soften the water in your showers, water heater or appliances. Even a whole-house carbon filter leaves the hardness minerals in place. Spots on glass, scale on fixtures and crusty showerheads take a softener or scale-control system, not a drinking water filter.

Which is right for you

• Choose a pitcher if: you mainly dislike the chlorine taste, drink a modest amount of water, and want the lowest upfront cost.
• Choose a carbon filter if: you want better-tasting water on demand at the kitchen sink, or chlorine reduction at every tap with a whole-house unit.
• Choose reverse osmosis if: you want lower TDS and that crisp, low-mineral taste for drinking and cooking, or you want one system certified for a broader list of contaminants.
• Combine them if: you want whole-home chlorine reduction plus low-TDS water at the kitchen sink. A whole-house filter or softener can work alongside an RO system, each handling a different job.