• Undersink Water Filter CTO Max for Hard Water

CTO Max Twin Under Sink Water Filter with Fluoride Removal for Hard Water

(1 customer review)

$539.00 inc. GST

You want to feel confident about the water you and your family drink every day. But in hard water areas like WA, NT, SA and parts of QLD, it’s not just the contaminants that are a concern,  it’s also the limescale that builds up in your kettle, clogs your filters, and affects your appliances over time.

  • UK-made ceramic filters remove fluoride, chlorine, chloramine, PFAS, microplastics, heavy metals, and organic contaminants.
  • US-made Inline phosphate cartridge made by Omnipure helps reduce mineral scale build-up
  • Certified to NSF/ANSI 53 & 42 standards for effective contaminant removal you can trust.
  • Hand-built in Sydney and backed by a 5-year housing warranty. Fully compliant with Watermark AS/NZS 3497:1998.
  • DIY-friendly setup — install this undersink water filter system yourself or get a plumber to do it for you. It’s simple either way.

Choose the tap for your under sink water filter

Retro with High Loop Metro with High Loop Chrome +$20.00 Antique with High Loop +$20.00 Stainless Steel High Loop Brushed Chrome +$85.00 Euro with Long Reach +$90.00 Side Lever High Loop 3 Way Mixer Chrome +$409.00 Side Lever Long Reach 3 Way Mixer Chrome +$349.00 3-Way Mixer Tap Standard Chrome +$319.00 Stainless Steel 3 Way High Loop Matte Black Mixer Tap +$449.00

Description

Certified Under Sink Water Filtration

This system meets the WaterMark specification AS/NZS 3497:1998 Amdt 1 2001 Drinking water treatment unit – Plumbing requirements.
Certificate Number 23124.

WaterMark Certification
NSF Certification

Everything You Want to Know (At a Glance)

Quick Answers

How often do I need to change the cartridges and how much do they cost?
CTO Max Cartridges: every 6–12 months, $219 discounted twin set (single cartridge $120).
Omnipure K5485-BB Phosphate Inline Cartridge: every 6 months or 5,700 litres: $79

Can I install this under sink filter myself?
Yes, you can install this undersink water filter yourself if you have basic plumbing skills. It’s WaterMark approved, meaning it meets Australian plumbing standards. If you prefer, your local licensed plumber can install it for you as well.

What contaminants does it remove?
This under sink water purifier removes over 130 chemicals incl. chlorine, chloramine, fluoride, herbicides & pesticides, bacteria, virus, PFAS, microplastics, heavy metals.

How do I replace the cartridges?
Simply twist open the housing, remove the old cartridge, insert the new one, and twist the housing closed. No special tools required – it’s quick and easy! 

What happens if it doesn’t work for me?
We’re here to guide you through every step, and while issues are rare, if something truly doesn’t work out, we’ll always honour our return policy on unused systems.

  • Filter output up to 10,000 litres, for optimal performance we recommend replacing the filters every 6-12 months
  • 0.9 Micron absolute
  • Dimensions: 23(W) x 45 (H) x 13(D)
  • Cartridge sizes: 9″ x 2.5″ 
  • Maximum flow rate: 2.5 litres per minute
  • Warranty: 5 years (housing)
Coldstream CTO Max

The system requires 2 of these cartridges to be replaced every 6-12 months for optimal performance.

You want clean, safe water for your family—and the Coldstream CTO Max helps you get there. This all-in-one cartridge removes over 130 contaminants, including Fluoride, Chlorine, Chloramine, PFAS, heavy metals, bacteria, and viruses. With its advanced dual-layer design, it fits standard benchtop water filters & undersink water filters and delivers peace of mind with every glass. Certified to NSF standards and built in the UK, it’s one of the best PFAS water filters available. 

Say goodbye to hard water hassles with the Omnipure K5485-BB phosphate inline cartridge. Designed to reduce limescale and mineral buildup, this 5-micron filter protects your water filter cartridges extends the life of your under sink water filter system. Perfect for hard water areas, it fits compactly in line before your filtration cartridge, preventing scale damage to your appliances. Made in the USA by trusted Omnipure, the K5485 offers reliable pre-treatment with easy installation. Designed to last up to 6 months or 5,700 litres, it keeps your water flowing smoothly and your system protected.

Installation of your twin undersink water filter system is straightforward with the included guide and complete package of parts. All necessary fittings, tubing, and adapters are provided for a seamless setup. 

We want to ensure your installation experience is easy and stress-free. Please reach out to our support team with any questions! 

Doulton Twin and Triple Undersink Water Filter Installation Diagram
Doulton Twin Under Sink Water Filter Ultracarb with fluoride removal component diagram
  • A – CTO Max Cartridge

  • B – CTO Max Cartridge

  • 1 – Housing Sump

  • 2 – Housing Cap

  • 3 – Stainless Steel Bracket

  • 4 – Pressure Limiting Valve (PLV)

  • 5 – John Guest Elbow (with red clips)

  • 6 – Brass Nipple

3 Simple Steps to Safer Water — with Free Shipping Australia-Wide:

Choose Your Filter – Order the CTO Max Twin for Hard Water and join our Water Tribe.

We Build & Send – Each unit is assembled in Sydney with care and shipped with tracking.

Install & Enjoy – Fit it yourself or have a plumber install it. Enjoy clean, balanced, great-tasting water from your tap.

How We Got Here And Why It Matters

When we first looked into water filters, we were completely overwhelmed. So many options, so much jargon. That journey led us to start Living Whole, one filter at a time — from our first water distiller to benchtop water filters and then reverse osmosis. Everything in our shop is something we’ve personally researched and trust. Now, after almost a decade in business and over 40 years of  combined experience, we’ve helped  thousands of families find the right filter for their home. Here is what they say:

Clean Water Shouldn’t Be Complicated — Just Clear, Safe, and Ready

At Living Whole, we understand that you simply want to feel at ease about the water you and your family use every day.

The problem is, tap water doesn’t just carry things like chlorine, heavy metals, and PFAS — in many parts of Australia, it’s also hard, leaving scale in your kettle, clogging your appliances, and shortening the life of your filters. That can leave you feeling frustrated and unsure. 

We believe you shouldn’t have to second-guess something as essential as your water.

Here’s how it works:

  1. Choose the CTO Max Twin Under Sink Water Filter with Fluoride Removal for Hard Water.
  2. We assemble everything and send it ready to install.
  3. Fit it once and enjoy clean, scale-reducing filtration every day.

Order your under sink water purification system today so you can stop worrying about what’s in your water — and start feeling calm, confident, and clear.

 

What You’re Avoiding

  • Limescale in your kettle, water filter, and on your tapware
  • Worries about PFAS, chlorine, or fluoride
  • Endless research and filter confusion

 

What You’ll Gain

  • Clean, better-tasting water — every time
  • Protection against scale build-up
  • Confidence in your wellness choices
  • A more sustainable, clutter-free kitchen

Choose Your Under Sink Water Filter Tap

All our under sink water filter taps include a base plate and connection fittings.
* Please Note: the width (W) refers to the dimension from the centre line of the tap body to the centre of the spout.

Chrome Retro Faucet with High Loop and Long Reach

Retro with High Loop

Standard Retro faucet in a high loop design and long reach.

125mm W x 235mm H

Chrome Metro Faucet with High Loop

Metro with High Loop

Standard Metro faucet in a high loop design.

160mm W x 250mm H

Chrome Antique Faucet with High Loop

Antique

Standard Antique faucet in a high loop design.

125mm W x 235mm H

Chrome Euro Faucet with Long Reach

Euro with Long Reach

Standard Euro faucet in a long reach design.

150mm W x 230mm H

Side Lever High Loop Mixer IT003855

Side Lever High Loop 3-Way Mixer Chrome

The Side Lever High Loop 3-Way Mixer Tap in Chrome features a sleek high-loop design, providing hot, cold, and filtered water from a single tap.

203mm W x 365mm H

Side Lever Mixer IT001169

Side Lever Long Reach 3-Way Mixer Chrome

The Side Lever Long Reach Mixer Tap features a simple yet elegant design, providing hot, cold, and filtered water from a single tap.

195mm W x 325mm H

3 Way Mixer Tap STD Chrome

3-Way Mixer Tap Standard Chrome

The 3-Way Mixer Tap Standard Chrome comes in a  sleek long-reach design, providing hot, cold, and filtered water from a single tap.

245mm W x 180mm H

Stainless Steel 3 Way High Loop Matte Black Mixer

Stainless Steel 3 Way High Loop Matte Black Mixer Tap

The Stainless Steel 3 Way Mixer Tap features a high loop design in a matte black finish, providing hot, cold and filtered water from a single tap.

225mm W x 400mm H

Additional information

Weight2.5 kg
Dimensions36 × 36 × 15 cm
Alkaliser

AlkaHydrate (made in Asia), Omnipure (Made in USA)

1 review for CTO Max Twin Under Sink Water Filter with Fluoride Removal for Hard Water

  1. Geoff

    Good product, feels well made and robust. The real benefit of this filter is the filter cartridges themselves which are certified to the US NSF standard, the results of the testing can be found online so you can be confident exactly what the filters are removing. Took about a week to receive the filter, it arrived already assembled with just the ministop valve, tap and connecting water tubes needing to be installed under the sink. All quite straight forward, but surprising no instructions were included in the box (just download it from the website).
    Be aware that as this uses two ceramic filters, there will be a little reduction in water pressure compared to other non ceramic water filters. Water tastes good.
    I did raise one question to which I received a prompt reply.

    • Living Whole

      Hi Geoff! Thank you so much for the detailed review! We’re happy to hear you’re satisfied with the product and the quality of our certified filters

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