Reverse Osmosis

Reverse Osmosis Water Filtration for South Florida Homes

Reverse osmosis (RO) pushes water through a semi-permeable membrane fine enough to reject dissolved solids, many disinfection byproducts, and a wide range of other contaminants most carbon filters can't touch — delivering bottled-water-quality drinking water from your own tap.

  • Removes dissolved solids most carbon-only filters pass through
  • Available as a whole-house system or a targeted under-sink unit
  • Paired with remineralization so treated water isn't flat-tasting

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How Reverse Osmosis Works

RO forces incoming water through a semi-permeable membrane under pressure. Water molecules pass through; dissolved minerals, salts, and many larger contaminant molecules are rejected and flushed to a drain line. Most residential RO systems stage this membrane behind a sediment pre-filter and a carbon pre-filter (to protect the membrane from chlorine and particulate) and follow it with a carbon polishing filter — sometimes a remineralization cartridge — before the water reaches your glass.

Because the membrane works on a molecular level, RO addresses a broader range of dissolved contaminants than a standard carbon filter alone, which is why it's the most common recommendation for households specifically concerned about PFAS, nitrates, or other dissolved compounds in their drinking water — always paired with an actual water test rather than assumed. See our PFAS in Florida drinking water guide for the current regulatory picture.

Whole-House RO vs. Under-Sink RO

Most South Florida homes don't run RO across the entire house — it's water- and pressure-intensive to treat every gallon that way, including water used for showers, laundry, and irrigation where drinking-water-grade purity isn't the goal. The typical setup is a whole-home filtration or softening system for the entire house, paired with a dedicated under-sink RO system at the kitchen tap and refrigerator line for drinking and cooking water. Whole-house RO does exist for households with a specific reason to treat all water to that level (severe well contamination, for example), but it's the exception rather than the default recommendation.

Dissolved solids

Reduces total dissolved solids (TDS) — minerals and salts that carbon filtration alone doesn't remove.

Broader contaminant range

Targets a wider range of dissolved contaminants than carbon-only filtration, verified against your actual test results.

Better taste

Removes the dissolved compounds most responsible for flat or metallic tap-water taste.

Point-of-use or whole-house

Sized either as a compact under-sink unit or, less commonly, a whole-house system depending on the household's actual water test.

How RO Compares to Other Filtration Methods

Carbon filtration (used in most whole-home systems, pitcher filters, and standard fridge filters) works by adsorption — contaminant molecules stick to the surface of activated carbon as water passes through. It's effective for chlorine, chloramine (with enough contact time), and many organic taste-and-odor compounds, but it does little to reduce dissolved minerals and salts. Ion-exchange softening, similarly, is built specifically around swapping hardness minerals for sodium or potassium — effective at its one job, not a general-purpose filter. RO is the outlier of the three because it works on a physical separation principle rather than a chemical one, which is what allows it to address a broader range of dissolved material regardless of chemical type — at the tradeoff of lower flow rate and some water sent to drain, which is exactly why it's usually paired with, rather than substituted for, carbon and softening rather than replacing them outright.

What RO Doesn't Do (and Why the Water Test Comes First)

RO membranes reject most dissolved solids, but a well-designed system is still built around what your water test actually shows — some situations call for a specific pre-treatment stage (like iron or hardness reduction) ahead of the membrane so it isn't fouled prematurely. This is also why we don't sell RO as a blanket fix before testing: the right system depends on your specific source water, whether that's a Palm Beach County municipal connection or a private well in Loxahatchee or The Acreage.

Maintenance and What to Expect

RO systems use replaceable pre-filters, a membrane (which lasts considerably longer than the filters, typically multiple years under normal residential use), and a post-filter. A storage tank holds treated water so you have on-demand flow at the tap rather than waiting on the membrane in real time. Expect a periodic filter change schedule set from your household's actual usage, plus an annual water-quality check to confirm performance.

Understanding TDS — What RO Is Actually Measured Against

What 'Total Dissolved Solids' Means for Your Water

Total dissolved solids (TDS) is the standard measurement used to gauge how much dissolved material — minerals, salts, and other compounds — is present in water, expressed in parts per million (ppm). It's the number most commonly referenced before and after an RO installation to show the difference the membrane makes, and it's a useful, simple way to track system performance over time without needing a full lab panel for every check-in.

TDS on its own doesn't identify which specific substances are present — two water samples with the same TDS reading can have very different compositions. That's why an initial water test still matters even when TDS is the number you'll track day to day: it establishes what's actually contributing to that number for your specific address, whether that's naturally occurring minerals from a limestone aquifer, water softener carryover, or something else worth a closer look.

As a rule of thumb, a well-functioning RO membrane should reject the large majority of incoming TDS — if a periodic check shows that rejection rate dropping meaningfully over time, it's usually a sign the membrane is nearing the end of its service life rather than a sign something is wrong with your source water.

Choosing a Membrane and Storage Configuration

What Actually Varies Between RO Systems

Beyond stage count, the two things that meaningfully differ between residential RO systems are the membrane's rated capacity (gallons per day) and how treated water is stored. A membrane rated well above your household's actual peak demand doesn't add benefit and can add unnecessary cost; one rated too close to your demand may struggle to keep the storage tank filled during high-use periods. Storage itself is either a pressurized tank (the traditional approach, providing instant flow at the faucet) or a tankless, pump-assisted design that filters closer to on-demand and takes up less cabinet space at the cost of a small delay at the tap. Neither is universally better — the right choice depends on your household's usage pattern and available cabinet space, which your installer walks through before recommending a specific configuration.

Reverse Osmosis FAQ

Common Questions

Does reverse osmosis remove PFAS?

RO membranes are effective against a wide range of dissolved contaminants, and are commonly recommended where PFAS is a concern — but performance depends on the specific system and membrane. See our PFAS in Florida drinking water guide for current EPA drinking water standards, and ask your local specialist for testing specific to your water before assuming any system's performance.

Does RO waste a lot of water?

RO systems send a portion of incoming water to drain as part of the filtration process. Modern residential systems are considerably more efficient than older designs; your installer can walk through the specific ratio for the unit recommended for your home.

Do I need whole-house RO or just under-sink?

Most South Florida households only need RO at the kitchen tap for drinking and cooking water, paired with whole-home filtration/softening for the rest of the house. Whole-house RO is a specialty recommendation for specific water-quality situations — not a default.

Will RO water taste flat?

Because RO removes dissolved minerals, some people notice a different taste versus tap water. Most residential systems include a remineralization stage specifically to address this.

How long does an RO membrane actually last?

Under normal residential use, a membrane typically outlasts several rounds of pre- and post-filter changes before it needs replacement — your installer checks membrane performance (via a TDS reading) at each service visit rather than replacing it on a fixed calendar alone.

Can RO be installed on a home with low water pressure?

Standard RO systems need a minimum incoming pressure to function efficiently; homes with low pressure sometimes need a small booster pump added to the system. This is confirmed during the initial assessment, not discovered after installation.

Find Out What's Actually in Your Water

A free water test shows your total dissolved solids and other readings before you choose between whole-house and under-sink RO.

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