Water Filter FAQ: Your Questions Answered

Under-sink filter fully installed: $300–$850. Reverse osmosis system fully installed: $800–$2,000. Whole house filter: $900–$4,500. Benchtop gravity filter: $50–$400, no installation cost. Annual maintenance varies from $80–$430 depending on system type. See our full cost guide for detailed breakdowns.

Under-sink single filter: $30–$80 per cartridge, replaced every 6–12 months. RO system: $150–$300/year averaged across pre-filters (every 6–12 months), post-filter (annually), and membrane (every 2–3 years). Whole house: $200–$430/year. Always budget for ongoing cartridge costs — they are significant over the system's life.

For taste and bottled water replacement: almost always yes. A family spending $30–$50/week on bottled water saves $1,500–$2,500/year. Most RO systems pay for themselves within 6–12 months. For health-specific concerns (PFAS, heavy metals, fluoride): the value depends on your specific water quality and risk tolerance. For basic chlorine taste removal: an under-sink carbon filter at $300–$500 installed is hard to argue against in cost-benefit terms.

Under-sink filters treat water at a single tap — your kitchen tap or a dedicated filtered-water tap. They are designed for drinking and cooking water and provide high-quality filtration at that point. Whole house (point-of-entry) filters treat all water entering your home — every tap, shower, dishwasher, and washing machine. They typically provide less comprehensive filtration than under-sink systems but cover the whole home. Many households use both: a whole house system for general water quality and an under-sink RO for drinking water.

No — standard activated carbon and carbon block filters do not remove fluoride to any meaningful degree. Fluoride ions are too small to be trapped by carbon filtration. To remove fluoride you need either a reverse osmosis system (removes 90–96%) or a dedicated activated alumina or bone char fluoride filter. If fluoride removal is your primary concern, make sure you choose the right technology before purchasing.

Tank and bore water are unregulated and may contain bacteria, viruses, sediment, heavy metals, and chemical contaminants not found in treated town water. The recommended approach: sediment pre-filter → carbon block filter → UV disinfection for any biological risk. If heavy metals or nitrates are a concern (common in bore water), add a reverse osmosis stage for drinking water specifically. Have your water tested before selecting a system — bore water composition varies enormously by location.

Yes, for any filter that connects to your mains water supply. Under-sink filters, RO systems, and whole house systems are all "plumbing work" under Australian state legislation and must be installed by a licensed plumber. Benchtop gravity filters and simple tap-attachment inline filters that don't penetrate plumbing are DIY-friendly. Using an unlicensed person for plumbing work is illegal, voids product warranties, and voids home insurance.

Under-sink filter: 1–2 hours including tap installation. RO system: 1.5–2.5 hours. Whole house filter (accessible pipe location): 2–4 hours. Whole house filter (difficult access, under-slab pipes): 4–8+ hours. Most plumbers complete under-sink and RO installations in a single service call.

The physical assembly of a filter unit — mounting the housing, inserting cartridges — is often DIY-friendly. The plumbing connection to mains water is not. A common approach for those wanting to save money: assemble the unit yourself and pay a plumber only for the connection and testing. This can save $100–$200 in assembly labour while keeping the legally required plumbing work with a licensed professional.

WaterMark is Australia's mandatory certification scheme for plumbing products that contact drinking water. It verifies a product has been tested to Australian and New Zealand Standards for safety and performance. Any water filter that connects to your plumbing must be WaterMark certified — this is a legal requirement under Australian plumbing codes. The WaterMark licence number appears on compliant products and can be verified at the ABCB WaterMark database (watermark.abcb.gov.au).

No — water filter installations are plumbing work, not building work, and do not require council approval. However, all plumbing work must be carried out by a licensed plumber who may need to issue a Certificate of Compliance (in some states). In apartment buildings, body corporate rules may require notification for any works affecting shared plumbing.

Most quality filters include a change indicator (pressure gauge or electronic reminder). In the absence of an indicator: change pre-filters and carbon filters every 6–12 months as a rule, sooner if water starts to taste like unfiltered tap water again. For RO membranes: a TDS meter ($20 from hardware stores) lets you test your filtered water quality — if TDS rises significantly, the membrane is degrading. Never skip RO pre-filter changes — this protects the expensive membrane.

Yes — cartridge replacement is designed to be DIY on most systems. Shut off the water supply, unscrew the filter housing, replace the cartridge, reseal, and restore water supply. The initial installation must be done by a licensed plumber, but ongoing cartridge maintenance does not. This is by design — the significant ongoing maintenance cost of hiring a plumber for every filter change would make the economics unworkable.

Yes — Australian tap water in all major cities meets the Australian Drinking Water Guidelines (ADWG) and is safe to drink without filtration. The question is not "safe vs unsafe" but "optimal vs adequate." Chlorine and chloramines are safe at regulated levels but cause the taste and odour many people find unpleasant. In PFAS-affected areas, water authorities are required to notify customers if levels exceed guidelines. For general mains water, filtering is a matter of preference and incremental health optimization — not necessity.

Perth has Australia's hardest tap water — high in dissolved calcium and magnesium, with significant scale buildup on appliances and fixtures. Adelaide has relatively high mineral content. Brisbane and South-East Queensland water is moderately hard. Sydney and Melbourne have relatively soft water. Hard water is not a health concern but affects appliance longevity (water heaters, dishwashers) and the effectiveness of soaps and detergents. A whole house water softener or specific hardness reduction filter addresses this.

Chlorine is added to all Australian municipal water supplies as a disinfectant. The smell and taste vary by season (more chlorine is added in warmer months when bacterial growth risk is higher), by distance from the treatment plant (chlorine dissipates over distance in the distribution network), and by local water temperature. A basic activated carbon filter removes chlorine and chloramines almost completely, producing clean-tasting water with no chlorine odour. This is the most common reason Australians install water filters.