Filter Tap vs Under-Sink Water Filter: Which Suits Your Kitchen?
Most of the time they are the same system. The under-sink filter is the part in the cupboard; the filter tap is where the filtered water comes out. The real choices are which tap, a separate filter tap or a 3-way mixer, which cartridge, and whether a jug or benchtop unit would do. Here is how each option compares in a Sydney kitchen, what it removes, what it costs at published retail prices, and what the install involves.
Choose a 3-way mixer if you want one tap on the sink and your mixer hole suits it, or a separate filter tap if you are keeping your mixer. Then choose the cartridge for what you want removed: carbon for the chlorine taste and smell, reverse osmosis if PFAS is on your mind. Anything connected to the water line is a job for a licensed plumber.
Licensed & insured · Lic #306457C
Talk to a licensed plumber about a filter tapFilter Tap or Under-Sink Filter? Usually Both
People search for a filter tap or an under-sink water filter as if they were rivals. In most kitchens they are two halves of one system.
The Under-Sink Filter
Filter housings mounted in the cupboard, fed from the cold water line. This is the part that does the filtering, and the part with cartridges to change.
The Separate Filter Tap
A small drinking water tap beside your mixer that pours only filtered water. Your mixer keeps doing hot and cold as before.
The 3-Way Mixer
One mixer for hot, cold and filtered water. In Puretec's Tripla range, filtered water has its own outlet and tubes inside the tap, so it never mixes with unfiltered water.Source: Puretec, Z1-T3 specifications
What sits under the sink: the same filter, two ways to pour it
A separate filter tap
Your mixer stays as it is for hot and cold. Puretec lists a 12.5 to 13 mm tap hole for its separate filter taps.
A 3-way mixer
It replaces your mixer, so it needs the hole to suit. Puretec lists a 33 mm tap hole for its Tripla T3.
Tap holes and separate waterways: Puretec TS200, RO270 and Z1-T3 specifications. Pressure limit: Puretec, citing AS/NZS 3500.1. Isolation valve: our water filter installation page.
Five Kitchen Options Side by Side
Here is how a jug, a benchtop unit, the two kinds of filter tap and a reverse osmosis tap compare on the things that matter day to day. Scroll the table sideways on a phone.
| What you get | Jug | Benchtop unit | Filter tap and under-sink filter | 3-way mixer and under-sink filter | Reverse osmosis filter tap |
|---|---|---|---|---|---|
| Where filtered water comes out | A jug in the fridge | A unit on the bench, fed from your tap | Its own tap beside the mixer | Your mixer, through its own waterway | Its own tap beside the mixer |
| Bench space | No | Yes | No | No | No |
| Cupboard space | No | No | Yes | Yes | Yes, plus a storage tank |
| New hole in the sink or bench | No | No | Yes, small | Not if the mixer hole suits | Yes, small |
| Licensed plumber | No | No | Yes | Yes | Yes, plus a drain connection |
| Chlorine taste and smell | Yes | Yes | Yes | Yes | Yes |
| PFAS | Depends on the cartridge | Depends on the cartridge | Depends on the cartridge | Depends on the cartridge | Near complete removal |
| Typical cartridge change | Every 4 weeks or 150 litres | Maker's schedule | 6 to 12 months | 6 to 12 months | Membrane every 1 to 3 years |
What Each Type of Filter Actually Removes
The tap is only the outlet. What ends up in your glass depends on the cartridge behind it.
Keep the starting point in mind. Sydney's tap water meets the Australian Drinking Water Guidelines, and the chlorine taste people notice comes from the chlorine and ammonia Sydney Water adds to keep it disinfected on its way to you. A filter tap is a choice for taste, smell and convenience, not a safety fix. NHMRC also notes that home filters can reduce useful things in the water, such as the chlorine residual that stops bacteria growing and the fluoride that protects teeth. If PFAS is your reason for filtering, NHMRC's advice is to choose a device proven to remove PFAS by independent testing.
Carbon
Carbon is what takes the chlorine taste and smell out. NSF/ANSI 42 is the standard for those aesthetic claims: chlorine, taste, odour and particles. Carbon does not remove bacteria or viruses.Source: NSW Health, Rainwater Treatment Fact Sheet
Ultrafine Filtration
Some kits go finer. Puretec's Ultra Z cartridge, used in its 3-way mixer kits, is rated at 0.1 micron, and Puretec says it reduces sediment, chlorine, taste and odour and protects against cysts.Source: Puretec, Z1-T3 specifications
Reverse Osmosis
Reverse osmosis pushes water through a very fine membrane and removes most dissolved chemicals. It sends a constant waste stream to the drain while it runs, and a 2020 study found it removed the PFAS tested almost completely.Sources: NSW Health; Herkert et al., 2020
What a Filter Tap Costs: Published Retail Prices
These are published prices from one Australian filter brand, so you can see how the options compare. Installation is on top, and depends on your sink, cupboard and pipes.
Published kit prices, product only (Puretec suggested retail, September 2026)
Puretec suggested retail prices including GST, as published on puretec.com.au for its mains water tap and filter kits and spare cartridges, retrieved 24 September 2026. Puretec notes reseller prices may vary. Installation is not included. These are market prices, not Mr Splash prices.
At the top end, Puretec's sparkling, chilled and ambient filtered taps are listed at $3,827.14 to $4,231.90. Whatever you choose, the plumbing part of the job is quoted once someone has seen the cupboard and the cold water line, so ask for a written, fixed price quote that names the tap, the filter and its certification.
Bench Space, Cupboard Space and Changing Cartridges
The practical differences show up after the install, every time you pour a glass or a cartridge falls due.
- A jug lives in the fridge. Brita recommends changing its MAXTRA PRO cartridge every 4 weeks or 150 litres, and drinking the filtered water within one to two days.
- A benchtop unit takes bench space. Puretec's countertop units connect straight to your existing tap, so nothing is plumbed in.
- An under-sink filter takes cupboard space instead. Puretec's general guide is to change standard cartridges every 6 to 12 months, and it designs them for do-it-yourself changes. Its 3-way mixer kits use a twist-off cartridge head.
- Reverse osmosis takes the most room. Puretec's RO270 comes with a 7 litre storage tank, needs a drain connection, and its membrane typically lasts 1 to 3 years.
- Boiling and chilled taps need power. They need a cold water connection and a power point under the sink.
- Whichever you pick, change the cartridge on time. A peer-reviewed study of household filters found that neglected ones can trap sludge, scale and slime that encourage bacteria to grow, which is the opposite of what you bought it for.
What the Install Involves
A jug and a benchtop unit need no plumber. Anything that connects to your water line does.
- Check the space. Where the cold water line runs, how much room the cupboard has, and where the tap will sit.
- Isolate the cold line. A new isolation valve lets the filter be turned off on its own for cartridge changes.
- Check the pressure. Where line pressure exceeds 500 kPa, an approved pressure limiting device must be fitted under AS/NZS 3500.1, as Puretec notes on its kits.
- Fit the tap. A separate filter tap needs its own small hole; a 3-way mixer goes in place of your mixer if the hole suits.
- Flush and leak test. Flush the new filter, fit the cartridge, turn the water on and check every joint.
In NSW, fitting anything that treats water is plumbing work that needs a licence. The Australian Building Codes Board adds a catch for taps bought online: it is legal to sell plumbing products without WaterMark certification, but if the product type is on the WaterMark Schedule of Products, a licensed plumber is not permitted to install an uncertified one. Check for the WaterMark before you buy. Filters that run at mains pressure, above 150 kPa, must also comply with AS/NZS 3497, NSW Health notes.
Our licensed plumbers (Lic #306457C) fit under-sink filters and filter taps, including ones you have already bought, with a fixed price quote before any work starts, a lifetime guarantee on our workmanship, and 0% interest payment plans available.
Which One Should You Choose?
Start with what you want the water to do, then pick the tap that gets you there.
Pick by what you want, not by the tap
Filtered water with no plumbing work at all
A jug or a benchtop unitTo keep your mixer and add filtered water
A separate filter tap with an under-sink filterOne tap on the sink for hot, cold and filtered
A 3-way mixer, if your mixer hole suitsPFAS taken out of your drinking water
Reverse osmosis, or a certified two-stage under-sink filterBoiling or chilled water from the same tap
A boiling or chilled filter tap, with a power point under the sinkFiltered water at every tap and shower
A whole house water filterPFAS: Herkert et al. 2020. Power point for boiling and chilled taps: our water filter installation page.
Filter Tap FAQs
What is a filter tap?
A tap that pours filtered water, fed by a filter under the sink. It is either a small separate tap beside your mixer or a 3-way mixer that pours hot, cold and filtered water from one spout.
What is a 3-way filter tap?
A kitchen mixer with a third, separate waterway for filtered water. It replaces your existing mixer, so you keep one tap on the sink. In Puretec's Tripla range, the filtered water has its own outlet and tubes, so it never mixes with unfiltered water.
Is a filter tap better than a jug filter?
It is more convenient: filtered water on tap, cartridges changed every 6 to 12 months rather than every 4 weeks, and nothing to refill. A jug needs no plumber and no cupboard space. Both take out the chlorine taste; for PFAS, check the certification of the exact cartridge.
Do I need a plumber to install a filter tap?
Yes. In NSW, connecting a filter to the water line is plumbing work, and WaterMark certified products must be installed by a licensed plumber. Changing the cartridge afterwards is usually something you can do yourself.
Do I need a second hole for a filter tap?
For a separate filter tap, yes: Puretec lists a tap hole of about 12.5 to 13 mm for its separate taps. A 3-way mixer usually uses your existing mixer hole instead, as long as the size suits.
How often do you change a filter tap cartridge?
Puretec's general guide is every 6 to 12 months for standard cartridges and every 1 to 3 years for a reverse osmosis membrane. Your own filter's instructions come first, and a neglected cartridge can do more harm than good.
Does a filter tap remove fluoride?
It depends on the filter. Brita says its jug cartridges are not designed to remove fluoride, while reverse osmosis reduces it: Puretec lists fluoride among what its RO270 reduces. NHMRC notes that home filters can reduce the fluoride that protects oral health.
Related: Water filter installation · Whole house water filters · Is Sydney tap water safe to drink? · Whole house or under-sink filter? · How often to change filter cartridges · WaterMark and licensed installation
