Tucson homeowners who are concerned about the quality and taste of their drinking water often ask us about reverse osmosis systems. Given what we know about Tucson's water supply — high mineral content, chlorine treatment, and elevated total dissolved solids — the question of whether reverse osmosis is worth the investment is a fair one. Here is an honest evaluation.
What Is Reverse Osmosis?
Reverse osmosis, commonly abbreviated as RO, is a water purification process that forces water through a semipermeable membrane under pressure. This membrane has pores so small that most dissolved substances, including minerals, salts, chlorine, lead, arsenic, fluoride, and many other contaminants, cannot pass through. The result is exceptionally pure drinking water. A typical residential RO system is installed under your kitchen sink and provides filtered water through a dedicated faucet.
What Does RO Remove from Tucson Water?
Tucson's tap water, while safe to drink by EPA standards, contains a range of dissolved substances that affect taste, odor, and potentially health. A quality RO system removes 95 to 99 percent of total dissolved solids (TDS), which gives Tucson water its distinctive mineral taste. It removes chlorine and chloramines used for disinfection, which cause a chemical taste and odor. RO removes lead, arsenic, nitrates, and other heavy metals that may be present in trace amounts. It removes fluoride, which some homeowners prefer to filter out. And it removes bacteria, viruses, and other microorganisms.
The Taste Difference Is Dramatic
For most Tucson homeowners, the biggest motivation for installing an RO system is the dramatic improvement in water taste. Tucson tap water has a TDS reading that often exceeds 300 to 500 parts per million. After RO filtration, that number drops to 10 to 30 PPM. The difference is immediately noticeable. Coffee tastes better. Tea is cleaner. Ice cubes are crystal clear. Many of our customers tell us they stopped buying bottled water entirely after installing their RO system.
How Much Does a Reverse Osmosis System Cost?
A quality under-sink RO system installed in a Tucson home typically costs $300 to $800 including installation. Whole-house RO systems, which are less common for residential use, can run $3,000 or more. Under-sink systems require filter replacement approximately once a year at a cost of $40 to $80. The RO membrane itself lasts 2 to 3 years and costs $50 to $100 to replace. Total annual maintenance cost is typically under $100.
RO vs. Bottled Water
If your household currently buys bottled water, the financial case for RO is easy. A family spending $30 per month on bottled water spends $360 per year. An RO system pays for itself in the first year or two and then costs less than $100 per year to maintain. You also eliminate the waste and hassle of buying, carrying, and recycling plastic bottles.
Common Concerns About RO
Some homeowners worry about the water waste associated with RO systems. Older systems produced 4 to 6 gallons of waste water for every gallon of purified water. Modern high-efficiency systems have improved that ratio to 1 to 1 or even better. Others wonder about the removal of beneficial minerals. While RO does remove calcium, magnesium, and other minerals, the amounts in tap water are nutritionally insignificant compared to what you get from food. The health impact of removing these minerals is minimal.
Should You Combine RO with a Water Softener?
In Tucson, the ideal water treatment setup for many homes is a whole-house water softener paired with an under-sink RO system. The softener protects your entire plumbing system, appliances, and fixtures from hard water damage. The RO system provides exceptionally clean, great-tasting drinking water at the kitchen sink and refrigerator. These two systems complement each other perfectly.
Find Out What Is in Your Water
ABC Water & Air provides free water testing for Tucson homeowners. We will measure your water's TDS, hardness, and other quality indicators, then help you determine whether an RO system, a water softener, or both make sense for your household. Call (520) 812-1597 to schedule your free test.