Every Phoenix homeowner faces a common challenge: hard, contaminated water that damages appliances, dulls hair, and degrades the taste of food and beverages. Deciding between a reverse osmosis system vs. water softener comes down to your lifestyle and how you hope to benefit from treating your water.
How the Systems Work
Reverse osmosis (RO) systems push water through a semipermeable membrane, filtering out up to 99% of contaminants like chlorine, lead, nitrates, and arsenic. These systems perform best when placed under the kitchen sink or used with a separate drinking water tap.
Water softeners use ion exchange to swap calcium and magnesium ions for sodium or potassium. By removing the minerals that cause scale buildup, you’ll notice softer skin, cleaner dishes, and smoother hair after showers. Plus, your plumbing appliances will run more efficiently and last longer.
What to Expect in Arizona
The local groundwater in Phoenix has some of the highest mineral content in the country. Water is considered “hard” at 7.0 to 10.5 grains per gallon (gpg) of dissolved calcium and magnesium. Anything over 10.5 gpg is “very hard.” According to the City of Phoenix’s 2024 Water Quality Report, the drinking water here has a total hardness of 9.2 to 20.1 gpg. These numbers are off the charts—no wonder so many homeowners seek hard water treatment in Phoenix!
Of course, water hardness isn’t the only concern. RO units focus on other types of contaminants, many of which are found in relatively high concentrations in Phoenix tap water:
- Chlorine: The highest allowed level is 4 parts per million (ppm). Samples of Phoenix tap water collected in 2024 contained 0.17 to 1.95 ppm.
- Lead: The Environmental Protection Agency (EPA) requires 90% of taps in a test area to fall below 15 parts per billion (ppb). While 90% of Phoenix taps are at 3 ppb or lower, two out of the 56 taps sampled in 2024 were above this range, one as high as 41.8 ppb.
- Nitrates: The highest allowed level is 10 ppm. Sample results came in as high as 8.2 ppm.
- Arsenic: The EPA has a goal of achieving no arsenic in the nation’s drinking water. Phoenix water tests as high as 8.3 ppb.
While these levels are all within allowed limits, they raise red flags for many Arizona families. Reverse osmosis systems filter out these and hundreds of other potential threats to preserve your home’s water quality and your family’s health.
Which System Should You Choose?
If you want better water for drinking and cooking, an RO system in Arizona provides clear, pure water straight from the tap. On the other hand, a water softener tackles hard water issues across your entire home. It’s the go-to solution for improving laundry performance, preventing scale buildup, and enhancing soap lather in the shower.
Want the best of both worlds? Consider combining these systems. A water softener removes dissolved minerals from every fixture, and the RO unit ensures water purity at the kitchen faucet. As a bonus, the softener protects the RO membrane from mineral overload, extending its lifespan.
Get Help Choosing the Best Water Filtration System in AZ
If you’re still not sure what’s best for your Phoenix home, turn to Aqua Science for personalized advice. We bring custom hard water treatment and reverse osmosis solutions to over 125,000 Valley homes. Our systems are backed by an A+ rating from the BBB and a 99.98% customer satisfaction rate. Ready for customized water treatment catered to your specific needs? Request a quote and find out which system is right for you.
