Reverse osmosis, or RO, uses pressure and a membrane as part of a treatment system. The exact model and its verified reduction claims matter more than the number of stages printed on the box. [4]
Follow the path of the water.
- Before the membraneAsk which prefilters the proposed design uses and what they protect.
- At the membraneAsk what the exact system is certified to reduce.
- At your tapDiscuss storage, dispensing and the water demand of your household.
- Over timeGet a written schedule for filters, membrane checks and servicing.
Seven questions before you choose RO.
- What water-quality result or household goal are we addressing?
- What is the full model number, including the cartridge or membrane?
- Which reduction claims are verified for that model?
- Will it serve one tap, and where will that tap be?
- How much space, pressure and drainage does the installation require?
- What are the replacement-part and service costs?
- How will performance be checked after installation?
One system is not every system.
Certification to an NSF/ANSI standard does not mean that every possible contaminant is reduced. Check the exact listing and the particular claim. [4]
Do not use a stage count, a taste comparison or a low meter reading as a complete drinking-water safety assessment. If your laboratory report identifies a concern, make sure the proposed approach specifically addresses it.
Quick questions
Is RO the same as a whole-home softener?
No. Discuss drinking-water goals and household hardness as separate needs, then decide whether either system fits.
What should I budget for ongoing care?
Request a current written quote for replacement parts and servicing, plus the recommended schedule for the exact system.