TL;DR
A reverse osmosis system is a water treatment unit that forces water through a semipermeable membrane fine enough to reject dissolved salts, arsenic, nitrates, PFAS, and most other contaminants that carbon filters pass. Residential point-of-use units live under the kitchen sink with prefilters, the membrane, a storage tank, and a dedicated faucet, sending a stream of reject water to the drain.
What it means
A reverse osmosis system is a water treatment unit that forces water through a semipermeable membrane fine enough to reject dissolved salts, arsenic, nitrates, PFAS, and most other contaminants that carbon filters pass. Residential point-of-use units live under the kitchen sink with prefilters, the membrane, a storage tank, and a dedicated faucet, sending a stream of reject water to the drain. On private wells it is the standard answer for contaminants that disinfection cannot touch.
Where it sits in the glossary
Reverse osmosis system is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
License: CC-BY-4.0 — quote freely with attribution to ProFix Editorial Team / ProFix Directory.