Reverse osmosis
A fine membrane at one drinking tap. Broader reduction of dissolved substances — with real trade-offs.
Dissolved substances
broad reduction
RO membrane
one drinking tap
Not whole-house
reject water + upkeep
What people use it for
- Broader cut of dissolved stuff at a single drinking tap.
- On wells: sometimes after tests show a specific dissolved issue (for example nitrate) — always driven by tests first.
Honest trade-offs
- Reject water — some water goes to drain.
- Upkeep — membranes and cartridges need schedules.
- Taste — low-mineral water tastes flat to some people.
- One tap — not your shower or whole house.
If you want more detail
People researching units often look for NSF/ANSI 58 and read which claims are certified. Treat “removes everything” marketing as a red flag. Education only — on city water, RO is a preference, not a requirement.