Why RO water tastes different
Reverse osmosis is thorough. EPA's WaterSense guide notes that RO removes beneficial minerals such as calcium along with contaminants. With most of the dissolved minerals gone, RO water tends to have a lower pH and a very clean, sometimes flat taste. Some people love it; others find it too plain.
An alkaline or remineralization stage is a small cartridge, usually with mineral media containing calcium and magnesium, placed after the membrane. Water picks up some minerals on the way to the faucet, which nudges the pH up and changes the taste.
Side-by-side comparison
| Factor | Standard RO | Alkaline RO |
|---|---|---|
| What it does | Pre-filters, RO membrane, carbon post-filter | Same stages, plus a mineral stage after the membrane |
| Minerals in finished water | Very low | Some calcium and magnesium added back |
| Taste | Clean, crisp, can seem flat | Often described as smoother or rounder |
| Best for | People who want the plainest possible water, or use it for specific uses like some appliances or aquariums | Everyday drinking, coffee and cooking for people who prefer a mineral taste |
| Maintenance | Pre/post filters and membrane on schedule | Same, plus replacing the mineral cartridge |
| Space | Under the sink with a dedicated faucet | The same footprint with one more cartridge |
| Ongoing cost factors | Filters, membrane, reject water | Filters, membrane, mineral cartridge, reject water |
What alkaline RO is and is not
Here is the honest framing. The mineral stage is about taste and preference. We do not make health claims about alkaline water, and you should be skeptical of anyone who does.
- The membrane does the heavy lifting. The mineral stage does not add any contaminant reduction; what the system reduces depends on its certification to NSF/ANSI 58 and the contaminants listed for that exact model.
- The pH change is modest. EPA lists pH among its secondary (non-enforceable) standards, which relate to taste, odor and appearance rather than health.
- The mineral cartridge wears out. As media is used up, the effect fades, so replace it on schedule.
Things that matter more than alkaline vs standard
- Certification. Look for NSF/ANSI 58 and check which contaminant claims the model actually carries.
- Efficiency. EPA says a typical RO unit sends at least five gallons to the drain per gallon treated; WaterSense labeled models send 2.3 gallons or less.
- Filter schedule. Missed changes affect taste and performance. Ask for a written schedule.
- Fit. Cabinet space, a drain connection and a spot for the dedicated faucet.
Which should you choose?
- Choose alkaline RO if you want RO treatment but prefer water with a little mineral taste for drinking and coffee.
- Choose standard RO if you want the plainest water and one less cartridge to change.
Living Water's under-sink alkaline reverse osmosis system is a multi-stage unit with its own faucet for homes, offices, apartments and gyms. Jorge can let you compare the taste after your free in-home water test. Call, text or WhatsApp (305) 793-5974.
https://www.epa.gov/system/files/documents/2025-01/ws-products-home-water-treatment-guide_v2_508.pdf
https://www.epa.gov/watersense/point-use-reverse-osmosis-systems
https://www.epa.gov/sdwa/secondary-drinking-water-standards-guidance-nuisance-chemicals
https://info.nsf.org/Certified/DWTU/
Updated 2026-10-17 · Living Waters · Jorge Canela, Water Quality Specialist