Whole-house filtration includes water used for drinking and cooking. Under-sink RO can add a separate treatment stage where a specific filtration preference calls for it, with remineralisation available on selected systems.
Evidence snapshot
- NHMRC (2025): The Australian Drinking Water Guidelines are a risk-management framework, not a single national pass/fail law. They separate health-based, aesthetic and operational considerations.
- NSF (2026): NSF standard numbers are not quality rankings. NSF/ANSI 42 covers stated aesthetic claims, 53 health-effect claims, 44 softeners, 55 UV and 58 point-of-use RO; the exact certified claim still has to be checked.
- US EPA WaterSense (2025): Point-of-use RO produces treated permeate and a reject stream. The US EPA's WaterSense work highlights both contaminant performance and water efficiency rather than treating all RO systems as equivalent.
- Water Analytics Australia (2026): WAA's current whole-home page describes staged sediment, carbon and complementary treatment, optional under-sink RO, consultation and ongoing filter support. Exact claims still need to match the supplied configuration.
These figures and standards are reference points, not a diagnosis of one home. Local water data, premises plumbing, flow and maintenance determine how they apply.
What the first observation can tell you
Start with the property itself. First compare cold water at two or three taps, then compare hot and cold. Check the utility's current notice and local report. If the issue appears only after water has sat in one fixture, investigate that fixture before changing the whole-house system. Carbon selection, media quantity and contact time should then be matched to free chlorine or chloramine rather than inferred from smell.
Where the claim stops
The decision should document feed-water conditions, daily demand, maintenance and concentrate-water expectations.
Keep the cartridge code, installation date, clean pressure and estimated volume in one service record. At change time, isolate the water, release pressure, inspect the housing and seal, fit the correct part and recommission according to the product instructions. A clean-looking cartridge may be chemically exhausted; a brown cartridge may still need pressure and volume data to judge its condition.
The operating detail that changes the answer
The combined system divides the jobs instead of implying that one stage is inadequate.
Separate current product evidence, research projects and future program promises. Each can be valuable, but they are not interchangeable. A customer should be able to see what is installed today, which claim applies to that configuration, what current program terms cover, and how support will handle later changes.
A practical household check
| Record | What to capture | Why it changes the decision |
|---|---|---|
| Current product | Check the exact installed specification | Keeps claims configuration-specific |
| Research | State the project scope and limits | Avoids borrowed authority |
| Support | Record service and program terms | Makes ownership concrete |
Use the same notes when requesting more than one quote. Suppliers then have to answer the same water, flow and ownership brief rather than redefining the problem around their preferred product.
Where Water Analytics Australia fits
WAA's role is to turn the household brief into a proportionate design. That starts with source water, treatment goal, realistic peak flow, available pressure, installation access and the preferred service approach. Depending on the job, the answer may be whole-home staged treatment, point-of-use RO, the benchtop system or a combination. The written proposal should explain why each stage is present, the conditions behind each claim and what the customer will need to maintain.
Related WAA guides
- Perth Hard Water Home: From White Scale to a Whole-House Plan
- Cleaner Water, Stronger Communities: The Impact Behind Every WAA Filter
- WAA Full Home Water Refining Systems
Common questions
Does a university project certify every WAA product?
No. Research can inform media development and testing. Commercial claims still need evidence for the exact product configuration and operating conditions.
What is the most useful measurement?
Use the measurement that matches the decision. Keep the cartridge code, installation date, clean pressure and estimated volume in one service record. At change time, isolate the water, release pressure, inspect the housing and seal, fit the correct part and recommission according to the product instructions. A clean-looking cartridge may be chemically exhausted; a brown cartridge may still need pressure and volume data to judge its condition.
What should WAA receive before recommending a system?
Provide the postcode, water source, household size, bathroom count, busiest-use pattern, observed issue, desired result and any laboratory report with its units and sample point.
Sources and further reading
- NHMRC: Australian Drinking Water Guidelines, version 4.0
- NSF: Standards for water treatment systems
- US EPA WaterSense: Point-of-use reverse osmosis systems
- Water Analytics Australia: Full Home Water Refining Systems
The next useful step
Write down the source, the result you want, peak-use flow and the evidence already available. Then ask for a recommendation that gives every stage a defined job, states the operating assumptions and includes the service plan. That is enough detail to compare a WAA proposal with any alternative without relying on fear or brochure language.