Buying guide
How to choose a water filter
Three decisions in order. Start with the source, then decide where you want the filtration, then pick the technology that matches your contaminants of concern. No upsell, no marketing — just the architecture.
Start with where the water comes from
Town water (mains) in Australia is treated to AS/NZS 3500 with chlorine or chloramine for disinfection. The water that arrives at your property is generally safe to drink, but the chlorine dose affects taste and odour and the supply network can pick up sediment and rust between the treatment plant and your house. Carbon filtration is the standard answer.
Rainwater tank is collected from your roof and never disinfected. It carries leaf debris, dust, bird droppings, and live bacterial load including E. coli and Giardia. Tank water needs both physical filtration (sediment + carbon) and UV sterilisation — UV alone leaves sediment, filtration alone leaves bacteria.
Bore or spring water varies by location and depth. Without a recent water test, specifying the right system is guesswork. Get a test first — your local council usually offers low-cost residential tests, or we can recommend a private testing service.
Decide where you want it filtered
Whole-house systems plumb into the mains supply line where it enters your property and filter every tap, shower, and appliance. They need a licensed plumber to install (Australian plumbing law), they need WaterMark certification (same reason), and they make sense when you own the property and care about more than just drinking water — chlorinated showers irritate skin, sediment-laden water shortens the life of dishwashers and washing machines.
Point-of-use systems filter one outlet — typically a kitchen tap with a dedicated filtered-water faucet. Cheaper, simpler, often the right answer if you only care about drinking water. Under-sink models are tidier; bench-top models pack up and move with you.
Pick the technology that matches your concern
- Carbon (block or GAC): chlorine, chloramine, taste, odour, basic chemicals. The workhorse stage in almost every system.
- Reverse osmosis: fluoride, PFAS / forever chemicals, dissolved heavy metals (lead, copper), nitrate, total dissolved solids. Slow but thorough.
- UV sterilisation:bacteria, viruses, protozoa. Doesn't filter — it inactivates pathogens with 254 nm UV-C light. Always paired with sediment + carbon upstream.
- Sediment: rust, sand, silt, suspended solids. Always the first stage on tank or bore water; protects the carbon stages downstream.
Most homes need a combination. Town water on a property you own typically wants sediment + carbon + polishing carbon at the mains line. Tank water adds UV after the carbon stages. Drinking-only setups concerned about PFAS or fluoride add a small RO unit at the kitchen tap.
FAQs — water filter selection
- Do I need WaterMark certification?
- Yes, if the system is plumbed permanently into a mains water line. Under Australian plumbing law any device connected to mains supply must carry WaterMark certification — that includes whole-house systems and most under-sink units. Bench-top and shower filters are not plumbed in and do not require WaterMark.
- Carbon block vs GAC carbon — what's the difference?
- GAC (granular activated carbon) is loose carbon granules — water flows through the gaps between particles, which gives it high flow but less contact time. Carbon block compresses carbon into a dense matrix — slower but with finer filtration and more uniform contact. For chloramine (used by Sydney, Melbourne, Brisbane, Adelaide, Canberra mains), specify catalytic carbon. For chlorine alone, either works.
- Is reverse osmosis worth it?
- Yes if your concern is fluoride, PFAS / forever chemicals, or dissolved heavy metals — RO is the only domestic technology that meaningfully reduces them. No if your concern is chlorine, taste, or sediment — RO is over-spec, slower, and wastes a few litres of brine for every litre of filtered water. Match the technology to the contaminant.
- How often do I need to change cartridges?
- Every 6–12 months for most systems, depending on water quality and household usage. Big Blue 20-inch cartridges last toward the longer end of that range because of their larger media volume; standard 10-inch cartridges land closer to 6 months. The pressure gauges on the Big Blue system tell you objectively when the differential rises — no guessing.
- Can I install this myself?
- Bench-top filters and shower filters yes — they connect to existing taps with no plumbing. Under-sink and whole-house systems should be installed by a licensed plumber, both for warranty / insurance reasons and because Australian plumbing law requires it on mains-connected installations.
Still unsure?
Bore water, mixed sources, very high TDS readings, or a multi-property setup all need a conversation, not a guide. Bring a recent water test if you have one — call us or visit the Wyong showroom and we'll spec the right system.