Reverse Osmosis Drinking Water in Round Rock
RO is the most thorough filter you can put under a kitchen sink. On Round Rock water, the details that matter are the pre-filter and who installs it.
Under-sink reverse osmosis costs about $400–$1,200 (Networx, 2026); whole-home RO runs $3,000–$10,000 installed (HomeBuddy, 2026). Round Rock water carried 302 ppm of total dissolved solids in 2025. RO removes most of those, plus the sodium a softener adds, for noticeably cleaner-tasting drinking water.
What RO removes from Round Rock water
The 2025 report lists total dissolved solids at 302 ppm, calcium from 45 to 95 ppm, sodium averaging 21.5 ppm and total alkalinity averaging 141 ppm (City of Round Rock). Those minerals are what you taste in plain water and what leaves film in a kettle. An RO membrane rejects most of them, along with the extra sodium from ion exchange softening. Nitrate, which reached 1.63 ppm at most against a 10 ppm limit, is reduced too.
Chloramine and the membrane
Most home RO membranes are damaged by chlorine-type disinfectants, and chloramine is one. That makes the carbon pre-filter the most important part on Round Rock water: it has to be rated for chloramine and changed on schedule. A system with a whole-house catalytic carbon filter upstream gets extra protection. Ask what pre-filter the unit uses before you buy.
Under-sink or whole-home
An under-sink system fits beneath a kitchen counter with a small storage tank and its own faucet, and it can feed the fridge. Whole-home RO needs a large storage tank, a pump to repressurize the water and a steady drain line. With city water that meets standards, few homes need it. Compare both on the Round Rock water treatment cost guide.
Upkeep and water use
Plan on regular pre-filter changes and an occasional new membrane; HomeBuddy's 2026 guide puts those at about $100 to $300 a year. Every RO unit also sends some water down the drain while it filters. Round Rock runs an active water conservation program, and it's worth matching that spirit: compare the stated ratio of drain water to filtered water, since newer designs waste far less than older ones.
Who can install RO in Texas
TCEQ's Class II Water Treatment Specialist license excludes reverse osmosis and deionization work unless someone with a higher class supervises; its Class III license covers RO. Licensed plumbers are exempt from the program (TCEQ). Ask which applies before work starts.
Questions homeowners ask
Does RO remove fluoride?
Mostly, yes. Round Rock's 2025 report lists fluoride at 0.21 ppm. If fluoride matters to you, talk with your dentist about whether that changes anything.
Can an RO system feed my refrigerator?
Usually, yes. Most under-sink units have a spare outlet for an ice maker or fridge line. Longer runs lower the flow a bit, so the installer should check the distance and the fridge's pressure needs first.
Ask for a free Round Rock water test
Spots on the shower glass, a chlorine-like taste, or an old softener making noise? Say what's going on and a water treatment specialist serving Round Rock will phone you.