Glossary
Whole house water filter glossary
The terms you'll see in quotes, reports and product specs, each explained in a sentence. Values quoted are from the Australian Drinking Water Guidelines (NHMRC).
- ADWG
- The Australian Drinking Water Guidelines, published by the NHMRC, which set health and aesthetic values for drinking water.
- Bypass valve
- A valve that routes water around the filter so the home keeps water during cartridge changes.
- Carbon block
- Compressed activated carbon that reduces chlorine taste and odour and some organic compounds.
- Catalytic carbon
- Carbon treated to break down chloramine more effectively than standard carbon.
- Chloramine
- A longer-lasting disinfectant made from chlorine and ammonia. Health guideline for monochloramine: 3 mg/L.
- Free chlorine
- Chlorine available to disinfect. Australian health guideline: 5 mg/L; many people taste it above about 0.6 mg/L.
- Hardness
- Dissolved calcium and magnesium, measured as mg/L calcium carbonate. Causes scale. Aesthetic guideline: 200 mg/L.
- Micron
- One thousandth of a millimetre. A 5-micron sediment filter traps particles larger than 5 microns.
- NATA
- The National Association of Testing Authorities, which accredits Australian laboratories. Lab results for PFAS and metals should come from a NATA-accredited lab.
- NSF/ANSI 42
- Certification standard for reducing aesthetic effects such as chlorine taste and odour.
- NSF/ANSI 53
- Certification standard for reducing health-related contaminants such as lead.
- NSF/ANSI 58
- Certification standard for reverse osmosis systems.
- PFAS
- Per- and poly-fluoroalkyl substances. Australian guideline values (2025): PFOS 8 ng/L, PFHxS 30 ng/L, PFOA 200 ng/L, PFBS 1,000 ng/L.
- Point of entry (POE)
- Treatment at the main water line after the meter. Whole house filters are point-of-entry systems.
- Point of use (POU)
- Treatment at one outlet, such as an under-sink kitchen filter.
- Remineralisation
- Adding calcium and magnesium back after reverse osmosis, for taste.
- Reverse osmosis (RO)
- A membrane process that removes most dissolved solids, including hardness and many contaminants. Used at a single tap.
- Scale control
- Salt-free treatment that changes how hardness minerals behave so less scale forms, without removing them.
- Sediment filter
- A cartridge that traps particles such as rust, silt and sand. Rated in microns; lower numbers catch finer particles.
- Total chlorine
- Free chlorine plus combined chlorine such as chloramine. The gap between total and free shows chloramine.
- Total dissolved solids (TDS)
- All dissolved minerals and salts. Affects taste. Aesthetic guideline: 600 mg/L.
- UV disinfection
- Ultraviolet light that inactivates bacteria, viruses and protozoa. Used for tank and bore water; certified to NSF/ANSI 55.
- Water softener
- Ion-exchange unit that swaps calcium and magnesium for sodium, removing hardness. Needs salt.
- WaterMark
- Australia's mandatory certification for plumbing products connected to drinking water.
- Whole house water filter
- A filter system installed where water enters a home (point of entry) so every tap, shower and appliance receives filtered water.
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