Begin with the result you need
UV and reverse osmosis describe different processes. UV is used for disinfection and does not remove dissolved chemicals. A reverse-osmosis proposal needs documented claims for the exact system and the substances of concern. Neither label by itself certifies a property's drinking outlet.
Compare the actual proposal
| Question | UV proposal | Reverse-osmosis proposal |
|---|---|---|
| Intended job | Which disinfection objective? | Which documented reduction claims? |
| Inlet conditions | What pretreatment and operating range? | What source conditions and pretreatment? |
| Installation | Power, monitoring and access? | Output, drainage, storage and access? |
| Maintenance | Component service and fault response? | Membrane and other component service? |
| Verification | Which final outlet and checks? | Which final outlet and checks? |
Ask about the rest of the route
Identify storage and plumbing after the proposed device. Ask how the completed system will be maintained and checked at the outlet you intend to use. Keep bypasses and fault arrangements visible in the diagram.
Do not assume it is always either/or
A property assessment may recommend a combination, another approach or no new equipment. Ask the designer to explain each stage against the actual report rather than copying a package used in another villa.
Put responsibility in writing
Keep the installer contact, service requirements, consumables and response to a fault with your system record. Confirm who can authorize downtime and where occupants obtain drinking water when the intended treatment is unavailable.
Prepare a fair comparison
Read the whole-house versus outlet guide, then use the free water check to assemble the questions for your property.
Questions worth asking
Does this guide assess water at my property?
No. It provides general context and a preparation checklist. A property-specific assessment needs appropriate inspection or testing.
What can I do without contacting a provider?
Create the free water checklist, print it and collect the records and questions described in this guide.
Sources & scope
Centers for Disease Control and Prevention · General treatment principles; not Bali-specific
Retrieved 2026-09-07 · Linked and summarized; verify product-specific claims independently.