Reverse osmosis drinking water systems
RO gives you a dedicated tap for drinking and cooking. Here's what it does well and what to know first.
A reverse osmosis system pushes water through a very fine membrane, along with pre-filters and a post-filter, and stores the treated water in a small tank for a faucet at the sink. It reduces dissolved solids, including sodium and many other substances. It's usually installed under the kitchen sink and sometimes run to the refrigerator.
Why pair RO with a softener?
Salt-based softeners add sodium as they remove hardness. University of Arizona Extension estimates roughly 7.9 milligrams per liter of added sodium for each grain per gallon of hardness removed, and advises against drinking softened water. An RO tap gives you low-sodium water for drinking and cooking while the rest of the house stays soft. Extension also notes hardness makes RO harder to run because it fouls the membrane, so softened water feeding the RO helps it last.
What about the wastewater?
Home RO units send part of the water they process to the drain. University of Arizona Extension puts it at roughly 3 to 8 gallons of wastewater for every gallon of treated water, which is why RO is sized for drinking and cooking, not the whole house. If you're on septic, ask the installer how the drain will be handled; Extension mentions routing RO wastewater outside to salt-tolerant plants to reduce the flow and salt load to the septic system.
Upkeep
- Pre-filters and post-filters changed on a schedule
- The membrane replaced less often
- A check of the storage tank pressure
Ask the company what the replacement schedule looks like for your water.
The water treatment company prices the job after it knows your water, your plumbing and what equipment makes sense. We don't quote prices, and a number given over the phone before anyone has tested the water or seen the install spot is only a starting point.
Where we connect you with help
Common questions
Is reverse osmosis the same as a softener?
No. A softener treats all the water for hardness. RO is a drinking-water filter at one or two taps.
Does RO work on well water?
Often, but test the well first. Hardness, iron and sediment may need treating before the RO so the membrane isn't fouled.
Related services
More background: Prescott hard water guide.
Spotty glasses, crusty faucets or a softener that quit?
Call now and a local water treatment company will help you figure out what your water needs.