Is an Under-Sink Reverse Osmosis System Worth It? Benefits, Costs, and Drawbacks
Reverse osmosis (RO) systems can remove a wider range of contaminants from tap water than standard carbon filters, but they are expensive and most households may not need one. The article says the value depends on local water quality: checking the latest water report is the best way to assess whether an RO system could address a household’s specific concerns.
RO membranes filter particles down to about 0.0001 microns, and many systems also include carbon filters. Tanked models store filtered water and work without electricity, while more expensive tankless systems filter water on demand and need power. The article identifies PFAS as a widespread concern, reporting that at least one PFAS compound has been detected in the water supplies of 98 of the 200 largest US cities; it also notes that RO systems waste water and that their drawbacks are largely linked to cost.
In short
- RO filters contaminants more finely than standard carbon filters.
- Local water reports can help show whether a household needs one.
- The systems can be costly and waste water.
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The case for
An under-sink RO system may be worthwhile for households whose water reports show contaminants they want to reduce, including some PFAS. Its fine filtration and, in many models, additional carbon filters can address a broader range of concerns than standard carbon filters, offering reassurance and more control over drinking water.
The case against
For households whose local water is already safe and does not contain contaminants of particular concern, an RO system may add little practical value. The upfront and ongoing costs, water waste and, for tankless models, electricity use can make it an unnecessary expense when a simpler filter or no additional treatment meets the household’s needs.