Reverse osmosis drinking water systems
Reverse osmosis is a point-of-use system, usually under the kitchen sink, that pushes water through a fine membrane to cut dissolved solids in the water you drink.
An RO system usually has a sediment pre-filter, a carbon filter, the membrane, a small storage tank and a carbon polishing filter, feeding a separate faucet at the sink. Some homes also run a line to the refrigerator's water and ice maker. It treats a few gallons a day for drinking and cooking, not the whole house.
Why do people in Cedar City add RO?
Total dissolved solids in Cedar City's water ranged from 180 to 804 ppm across its sources in 2025, according to the city's water quality report, and sulfate reached about 347 ppm at the high end. Dissolved solids affect taste, and they're what leaves the residue in a kettle or coffee maker. RO is designed to reduce them. Households with a softener sometimes add RO for drinking water, since softened water carries a bit of added sodium from regeneration.
What should I know before installing one?
- It needs a drain connection. RO sends some water to the drain as it filters. Ask how much the system you're considering uses.
- Filters need changing. Pre-filters and post-filters are replaced on a schedule, and the membrane less often. Ask what the parts cost and how often.
- Space under the sink. The tank and filter housings take room. Some systems are tankless and more compact.
- Hardness shortens membrane life. On hard water, a softener ahead of the RO usually helps the membrane last.
What about private wells?
If your home is on a private well rather than a city system, have the water lab-tested before choosing equipment. The test results, not a sales pitch, should decide what treatment you need.
What affects the price?
- Tank versus tankless system
- Adding a refrigerator or ice-maker line
- Faucet style and countertop drilling
- Ongoing filter and membrane changes
The company you're connected with prices the job after testing your water and looking at the install spot. We don't quote prices, and a number given over the phone before anyone has seen your plumbing is only a rough starting point.
Where we connect you with help
Common questions
Does reverse osmosis treat the whole house?
No. A typical RO system serves one faucet and sometimes the refrigerator. For the whole house, a softener and filter handle hardness and particles.
Can RO be added if I already have a softener?
Yes. It's a common combination, and softened feed water can help the RO membrane last longer.
Related services
More background: Cedar City hard water guide.
Crusty faucets, spotty dishes or a softener that quit?
Call now and a local water treatment company will help you figure out what your water needs.