The best under-sink water filters in Australia

An under-sink filter is what most home owners should end up with. It is out of sight, it filters every drop from the kitchen tap at full pressure, and the running cost is a fraction of a jug’s. The trade-off is that it is plumbing, with everything that implies in Australia.

Two kinds of under-sink filter

Inline direct-connect units are a single cartridge that sits in the cold water line. The Brita A1000, Frizzlife direct-connect and Puretec Z6 work this way. They are compact, they run your existing tap, and cartridge changes are a twist. The limit is that a single cartridge has to do everything.

Housing systems use standard 10 inch housings, one per stage, and usually a separate small tap. The Stefani single, twin and triple systems are the common example. They take up more cupboard, but the housings accept generic cartridges from any brand, and you can put a sediment stage in front of the carbon, which is essential on tank or bore water.

Certification is where the price differences hide

Two units that look identical can differ in what they have been tested to do. NSF/ANSI 42 certification means independent testing for chlorine, taste and odour. NSF/ANSI 53 means testing for health contaminants such as lead and cysts, to a stated reduction. The Frizzlife unit carries both, which is unusual under $150. Products with no certification may still work; you are simply taking the manufacturer’s word for it.

Micron ratings

A 5 micron sediment cartridge stops grit. A 0.5 to 1 micron carbon block stops cysts. Puretec’s Z6 goes to 0.1 micron, which is fine enough to reduce bacteria as well. Finer is not automatically better on good city water: it costs flow and cartridge life. On tank water, finer is the whole point.

Installation in Australia

Plumbed filters are licensed plumbing work in most states, and the product should carry WaterMark certification. Budget a couple of hundred dollars for the plumber if you are not doing it under your own licence. If a dedicated tap is going in, check the benchtop material first; drilling stone is a specialist job.

The picks

The Frizzlife unit is our overall pick for certified filtration at a price most people will pay. Choose the Puretec PureMix Z6 if you want an Australian company with local support, cartridges that ship from Adelaide, and 0.1 micron filtration. Tank and bore households should choose the Stefani twin system for its sediment pre-filter and cheap standard cartridges. The Brita A1000 is the cheapest way to get plumbed filtration on good city water.