6-Stage Under-Sink RO | From $690 | WAA – Water Analytics Australia (WAA)

WAA under-sink RO system and mixer in a bright Australian kitchen

Six stages below. One tap above.

Enjoy reverse osmosis drinking water without a whole-house installation. Our non-electric, six-stage under-sink system pairs with a 3-way mixer for regular hot, cold and filtered drinking water.

Have a question before ordering?

Can’t install whole-house filtration? Start at the kitchen sink.

Living in an apartment, renting your home, or unable to access the main water supply? Explore a dedicated drinking-water solution for your kitchen.

The WAA six-stage RO system treats water at the filtered drinking-water outlet. It works independently of whole-house filtration, with the unit and storage tank tucked beneath the sink.

Installation depends on cabinet space, water pressure and plumbing access, plus any required property approval.

One mixer. Three water options.

Regular hot water for everyday kitchen tasks. Regular cold water for washing. A separate filtered drinking-water supply from your six-stage RO system.

A compatible 3-way mixer can replace your existing mixer using the same opening, avoiding an additional drinking-water tap hole. We check the fit before installation.

The filtered supply is at ambient temperature. This system does not heat or chill water. The regular hot and cold supplies do not pass through the RO system.

Six stages. Each with a purpose.

Sediment and two carbon stages prepare the incoming water before reverse osmosis. Post-carbon polishing refines taste and odour, followed by mineral finishing.

The RO membrane reduces a range of dissolved substances that sediment filtration alone does not address. The final mineral media adds minerals after RO and can influence taste and pH.

Performance depends on incoming water quality, operating conditions and regular maintenance.

Discuss My Water Supply

No Electricity Required

The filtration unit and a separate storage tank sit inside a suitable kitchen cabinet. A cold-water feed, filtered-tap connection and drain connection are required.

Filtration unit: approximately 450 H × 360 W × 200 D mm.
Storage tank: approximately 340 H × 230 W × 230 D mm.

Allow extra clearance for tubing, fittings and filter changes. The standard system operates without electricity where incoming water pressure is suitable. Send us photos of your sink and cupboard so we can check the setup.

Ongoing filter care

Simple care. Continued performance.

Keep your system performing as intended with simple annual filter changes. We recommend replacing all filter cartridges, including the RO membrane, every 12 months. Earlier replacement may be needed depending on your water quality and household usage. Speak with WAA for help choosing the right replacement filters and planning your annual service.

Installation should be assessed for your kitchen. The selected mixer, plumbing requirements and installation arrangements will be confirmed in your quote.

First, prepare the water.

Three pretreatment stages support the reverse osmosis process.

01 — Sediment filtration

The first stage captures sand, silt, rust and other suspended particles before water reaches the carbon filters.

02 — Granular activated carbon

Activated carbon helps reduce chlorine and unwanted tastes and odours in the incoming water.

03 — Carbon block

A carbon block provides further pretreatment before the reverse osmosis membrane.

Then, refine your drinking water.

Reverse osmosis, taste polishing and mineral finishing complete the process.

04 — Reverse osmosis

The RO membrane reduces a range of dissolved substances, with performance depending on water quality and operating conditions.

05 — Post-carbon polishing

A final carbon stage helps refine taste and odour after reverse osmosis treatment.

06 — Mineral finishing

Mineral media adds minerals after RO filtration and can influence the finished water’s taste and pH.

Planned rollout: February 2027

Australian-made filters are on the way.

Our planned Australian-made replacement-filter range will roll out to compatible whole-home systems as customers’ filters become due. It is the next step in bringing WAA’s filter development closer to home.

See the Filter Initiative

Research with Curtin University

Our Curtin University collaboration explores filtration materials and their performance. It forms part of WAA’s ongoing work to improve the filters customers use at home.

Explore Curtin Research

Filter research with UNSW Sydney

WAA has worked with UNSW Sydney’s School of Chemical Engineering to investigate water-treatment materials, including research into selected contaminants.

Explore the project and its findings to see how materials research informs our development programme.

Explore UNSW Research

A few things to know before you choose.

Do I need a whole-house system first?
No. This is a standalone kitchen drinking-water system and can also complement compatible whole-house filtration.

What is included in the price?
$690 includes the six-stage RO system and Dedicated Tap, supply only. $990 includes the system and your selected 3-Way Mixer instead of the Dedicated Tap, supply only. The $1,290 installation package includes a 3-Way Mixer. Choose Supply only or With installation above, then select your tap style and finish. With installation requires a 3-Way Mixer; Dedicated Tap is available with Supply only. WAA will contact you to arrange installation.

Will I need another hole in my benchtop?
A compatible 3-Way Mixer can use your existing tap opening. A Dedicated Tap needs a suitable separate 25 mm hole. Cabinet space, plumbing and drain connections still need to be checked.

Does all water from the mixer pass through RO?
No. Regular hot and cold water remain separate. Only the filtered drinking-water supply comes from the RO system, at ambient temperature. The system does not heat or chill water.

Is it suitable for a rental or apartment?
It can be an option where whole-house installation is not practical, subject to kitchen suitability and any required property approval.

Does RO require electricity or a drain connection?
No electrical connection is required where incoming water pressure is suitable. A drain connection is required for the concentrate stream produced during filtration. Water use varies with operating conditions.

Images are illustrative renders. Actual equipment placement and plumbing may vary.

Have a question before ordering?

Your kitchen. Your water. Your options.

Let’s find the right setup for your kitchen.

Have a question before ordering?

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Silver 7606S	Black 7606BL
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Silver 7624S	Black 7624BL
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WAA RILL™ 6-Stage Undersink RO System

Already own this system?

WAA RILL™ 6-Stage Undersink RO System

Six stages below. One tap above.

Can’t install whole-house filtration? Start at the kitchen sink.

One mixer. Three water options.

Six stages. Each with a purpose.

No Electricity Required

Ongoing filter care

Simple care. Continued performance.

First, prepare the water.

01 — Sediment filtration

02 — Granular activated carbon

03 — Carbon block

Then, refine your drinking water.

04 — Reverse osmosis

05 — Post-carbon polishing

06 — Mineral finishing

Australian-made filters are on the way.

Research with Curtin University

Filter research with UNSW Sydney

A few things to know before you choose.

Your kitchen. Your water. Your options.

Let’s find the right setup for your kitchen.

WAA RILL™ 6-Stage Undersink RO System