Reverse osmosis drinking water systems
Reverse osmosis pushes water through a fine membrane to remove most dissolved solids. Here's when it's worth adding.
A reverse osmosis system usually sits under the kitchen sink with its own small faucet and storage tank. Water passes through pre-filters, a semi-permeable membrane and a final polishing filter. The result is drinking and cooking water with a much lower mineral and salt content than what comes out of the main tap.
Why do people here add RO?
St. George's 2024 water quality report lists total dissolved solids in city groundwater ranging from 118 to 936 parts per million, and sodium from 5 to 153 parts per million, depending on the source. A softener adds a bit more sodium or potassium. Many people simply prefer the taste of RO water for drinking, coffee and ice, and it cuts down on spots in kettles and coffee makers.
What does RO not do?
- It doesn't soften the rest of the house. Showers, laundry and the water heater still need a softener.
- It isn't a fix for a known contamination problem on its own. If a test shows something specific, ask the company which certified product reduces it.
- It sends some water to the drain as it filters. Ask how efficient the system is and whether a permeate pump or newer design wastes less.
Install and upkeep
- Placement. Under the sink, with room for the tank and access for filter changes.
- Connections. A feed line, a drain connection with an air gap, and a hole in the counter or sink for the faucet.
- Optional lines. Many homeowners run a line to the refrigerator for ice and water.
- Filter changes. Pre-filters and post-filters are changed on a schedule, and the membrane less often.
What affects the price?
- Number of stages and the tank or tankless design
- Countertop drilling and a fridge line
- Bundling with a softener or filter install
The water treatment company prices the job after learning about your house, your water and, for installs and repairs, the spot where the equipment goes. We don't quote prices, and any number given over the phone is only a rough starting point until someone has seen the setup.
Where we connect you with help
Common questions
Should RO go before or after the softener?
Under-sink RO is normally fed softened water, which helps the membrane last. The installer will confirm for your setup.
Can you service an RO system I already have?
Yes. Many companies change filters and membranes on existing units. Note the brand when you call.
Related services
More background: Washington County hard water guide.
Spots on the glasses, crust on the faucets, or a softener that quit?
Call now and a local water treatment company will help you sort it out.