Reverse Osmosis Drinking Water for Rochester
RO is the kitchen-sink partner to a softener. It strips most dissolved minerals and salts from the water you drink and cook with.
Reverse osmosis pushes water through a membrane that holds back most dissolved salts and minerals. An under-sink system costs about $200–$800 plus $100–$300 to install, and whole-home RO $1,000–$4,800 (HomeAdvisor). In Rochester, RO is most often paired with a softener to remove the sodium softening adds.
Why RO follows a softener
RPU's 2025 report lists sodium in city water at no more than 8.77 ppm, and it adds a note that home water softening can increase the level of sodium. That's how ion exchange works: calcium and magnesium are swapped for sodium. On 17-grain water, the swap is substantial. An RO system at the kitchen sink removes most of that sodium, along with sulfate and other dissolved minerals, so drinking water ends up lower in both hardness and salt.
Under-sink or whole-home
Under-sink RO treats one faucet, sometimes with a line to the refrigerator. HomeAdvisor lists these at $200 to $800, with $100 to $300 for installation. Whole-home RO treats every tap and costs $1,000 to $4,800. HomeAdvisor describes whole-home systems as best suited to wells or water with high contaminant levels. On softened city water, most Rochester households need RO only where they drink.
Efficiency and upkeep
- Waste ratio. High-efficiency systems send about 1 gallon to the drain per gallon filtered; older designs can waste up to 4 (HomeAdvisor).
- Filters. Prefilters protect the membrane and are changed every 6 to 12 months, roughly $40 to $300 a year.
- Membrane. Lasts two to five years, about $30 to $100 to replace.
- Standard. Look for systems tested to NSF/ANSI 58.
If RO water tastes flat
Water with most of its minerals removed can taste flat to some people. A remineralization cartridge adds a little calcium and magnesium back after the membrane. HomeAdvisor lists an alkaline remineralization kit at $150 to $300. It's optional; many households are happy with plain RO water, especially for coffee and ice.
Space and plumbing
An under-sink unit needs cabinet room for the filter housings and a small storage tank, a spare faucet hole or a new one drilled, and a drain connection. Tankless models save space but draw more power and cost more. For softener and filter prices alongside RO, see the Rochester water treatment cost ranges.
Questions homeowners ask
Does RO remove fluoride?
Largely, yes. RO membranes reject most dissolved ions, including the fluoride RPU adds at about 0.7 mg/L. If that matters to you, talk to your dentist about other sources.
Can I skip the softener and use only RO?
You can, but only the RO faucet gets treated water. At 17 grains, pipes, fixtures and the water heater would still take the scale.
Book a free hardness test in Rochester
Tell us what you're dealing with: new softener, a unit acting up, or taste. A local water treatment specialist serving Rochester calls you to set a time.