Triple Whole House Hard Water, Heavy Metal & Chlorine Reduction Filter System | 20" x 4.5" High Flow | Watermark (GT1-108-OSP)

Triple Whole House Hard Water, Heavy Metal & Chlorine Reduction Filter System

What is water hardness & limescale and why should you treat it?

“Hard Water” contains high levels of naturally-occurring dissolved minerals, such as Calcium and Magnesium. When dissolved in water, these minerals form sticky “scale” crystals that can cause the following problems:

• Scale can clog pipes and build up in and around fixtures such as taps and toilets;
• Scale has a tendency to form in hot water systems and appliances such as washing machines, kettles and coffee machines;
• Scale bonds with detergents to form soap scum which leaves a film and prevents proper cleaning (i.e white spots on glass, white soap scum residue on clothing).

The level of hardness in your water depends on where your water supply comes from. For example, bore water is a common source of water hardness, and many geographical regions (i.e. Western Australia and South Australia) are renowned for soils with high mineral content.

If you live in an area with hard water, consider whether a Triple Whole House Hard Water Conditioning System with a Sediment, Carbon and OneStop Plus™ Water Conditioning Cartridge is the best option to reduce not only Chlorine and chemicals, but to help you combat the effects of scale build-up in your home!

The OneStop Plus™ system is a water conditioner designed to protect open circuit piping from limescale deposits. It can be installed as a Point-of-Entry device, for both cold and hot water, or as a Point-of-Use device, installed directly before the equipment that needs to receive treated water (saunas, dishwashers, washing machines, coffee machines, etc.). OneStop Plus™ media is a proprietary blend of two resins designed to treat hardness/scale build up and reduce heavy metals. This media is fit for use with drinking water, and tested as compliant to the following certifications:

• The Scale Reduction Resin component is compliant to the National Sanitation Foundation Standard NSF/ANSI No. 61.
• The Heavy Metal Reduction Resin component is compliant to the Council of Europe Resolution ResAP (2004) 3.

How It Works

OneStop Plus™ prevents limescale by interacting with the calcium carbonate molecules, turning them into harmless soft crystals. These soft carbonate crystals continue to flow with the water, however post-treatment, these molecules exhibit a significantly reduced ability to adhere to surfaces, and are simply washed away down the drain. At the same time, these soft crystals “snowball” their way through the water, attracting free calcium carbonate molecules and dramatically reducing existing limescale deposits.

Balanced Water Chemistry for Corrosion Prevention

A significant advantage of the OneStop Plus™ system is that it retains the natural minerals in the water, maintaining the water’s mineral balance. This balanced saturation helps prevent the corrosive conditions commonly associated with conventional salt-based water softeners, which strip minerals and can destabilize water chemistry. This ensures your water remains safe for piping and appliances while mitigating limescale problems.

Important Notes

While the OneStop Plus™ system effectively conditions water to prevent and reduce limescale deposits, it does not remove calcium or magnesium from the water. Users may still observe the presence of these minerals, such as calcium deposits on surfaces if the water is allowed to dry. However, these deposits are less adherent and easier to clean compared to untreated water. For best results in these areas such as glass shower screens, it is recommeneded to squeegee or dry the glass after use to prevent spotting.

For optimal performance, consider pairing the OneStop Plus™ with a carbon filter upgrade to further reduce chlorine, heavy metals, and other contaminants.

By choosing the OneStop Plus™ system, you are opting for an environmentally friendly, low-maintenance, and highly effective solution to combat the effects of hard water while preserving your water’s natural balance and essential minerals.

For a full list of technical specifications, including installation information, see Specs/Performance Tab.

Heavy Metal Reduction

As an added bonus, OneStop Plus™ media has the secondary effect of adsorbing heavy metals, without leaching them back into the water! For the best results in this system, and for added peace of mind, we strongly recommend selecting the optional Carbon Filter upgrade to the 0.5 Micron Lead and Heavy Metals Reduction Cartridge (pictured below), which will help reduce heavy metals for even better heavy metal reduction results!

NOTE: Above results based on OSP cartridge only. Additional performance possible when utilising GT4-19LRC

Features & Benefits

Retains Essential Minerals:

• Converts limescale into harmless crystals.
• Reduces existing limescale deposits.
• Prevents limescale build-up without using chemicals, electricity, or salt.
• Safe for drinking water applications.

Environmentally Friendly:

• No water waste from backwashing.
• No regeneration cycle required.
• Salt-free solution for improved sustainability.
• Increases the efficiency of boilers and other equipment in contact with treated water.

Reduces Heavy Metals:

• Effectively reduces levels of copper, lead, zinc, and cadmium.
• Long-lasting cartridge life; water hardness is not a limiting factor.*
• Compatible with most municipal water supplies (see Specifications).

System Contains:

• 3x 20" x 4.5" High Flow Housings - Pre-assembled with bracket affixed
• 1x Sediment Pre-Filter (Stage 1)
• 1x One Stop Plus Water Conditioner Cartridge (Stage 2)
• 1x 20" x 4.5" Coconut Carbon Block Filter (Stage 3)
• Opening Handle - Suit 4.5" Housings (GT17-2S)
• 3x 1/4" Plugs & Seals to suit 20" Housing Pressure Gauge Port

Basic Technical Specifications:

• Dimensions:
  • Height - 70cm
  • Width - 62cm
  • Depth - 20cm
• Filter Cartridge Size: 20" x 4.5"
• Ports: 1" Female BSP (Stainless Steel)
• Max Pressure: 500 kPa (Exceeding this requires Pressure Reduction Valve)
• Recommended Pressure: 350 kPa - 500 kPa
• Temperature: 0.5°C - 37.8°C
• Max Flow: 60L/Min
  • Service Flow 15L/Min for best results

WaterMark Certified

This Water Filter System is certified to WaterMark Standard AS 3497 under Certificate Number 23247. WaterMark certification is a mandatory requirement under Australian law for water filter systems to be installed by licensed plumbers. Products bearing this certification meet rigorous Australian plumbing and water safety standards, ensuring compliance and reliability. Our WaterMark-certified filter systems are hand-assembled in Australia and undergo random batch testing to maintain the highest quality and workmanship, giving you confidence in the safety and performance of your water filtration products.

Filter Cartridge Options

You will find several cartridge options for both the 1st and 3rd cartridge, all of which may be useful in different scenarios. Below are the most common configurations used, please note these are general recommendations only and may not always suit your requirements. If you are unsure, please contact us prior to purchase to ensure you are getting the correct filters.

Option 1 - Standard, Chlorinated Mains Water

This is the set of filters that suits the largest number of applications. It will cover dirt/sediemnt, Hardness & Chlorine and other chemicals.

1. 5 Micron Polyspun Sediment Filter (GT2-28K)
2. OSP
3. 5 Micron Coconut Carbon Block (GT4-19CTO)

Option 2 - Premium, Chlorinated Mains Water + Heavy Metal Filter

This set is the premium option that uses a specialist carbon filter for targeting everything mentioned above, including heavy metals. This carbon block is rated to 0.5uM so ideally this should only be used where the mains water pressure is between 350 - 500 kPa. If you susspect your water pressure is "ok" or "lower than average" this cartridge may not be suitable.

1. 5 Micron Polyspun Sediment Filter (GT2-28K)
2. OSP
3. 0.5 Micron or 5 Micron Lead Reduction Coconut Carbon Block (GT4-19LRCP5 or GT4-19LRC05)

Option 3 - Premium, Chlorinated Mains Water + Chloramine Reduction

This set is recommended for mains water supplies that use Chloramine disinfection. Chloramine is the primary disinfection method used in most metropolitian cities in Australia, Including Sydney, Brisbane, Melbourne and widely used in WA and SA.
The easiest way to find out if your water contains Chloramine is to contact your local water provider (or council).

This carbon block is rated to 0.5uM so ideally this should only be used where the mains water pressure is between 350 - 500 kPa. If you susspect your water pressure is "ok" or "lower than average" this cartridge may not be suitable.

1. 5 Micron Polyspun Sediment Filter (GT2-28K)
2. OSP
3. 0.5 Micron Chloramine Reduction Catalytic Coconut Carbon Block (GT4-19CRC)

Alternative Water Supplies - Bore Water* Etc.

Due to the wide range of potential contaminants in bore water, we cannot provide a recommendation for filter cartridges unless the water has a valid water analyis. Click here for further details on water analysis.

Optional Extras & Add-ons

Pressure Gauges - Monitor Performance and assist with troubleshooting

Enhance your whole house water filter system with pressure gauges to ensure peak performance and efficiency. These handy tools allow you to monitor water pressure before and after the filter, making it easy to identify when maintenance or filter replacement is needed. By preventing clogs and ensuring consistent water flow, pressure gauges protect your plumbing system and maintain water quality. A simple yet effective addition, they help you troubleshoot issues like leaks or blockages, saving time and extending the life of your filtration system.

If you are unsure of your water pressure before purchase, you can use out handy Water Pressure Test Kit to ensure the install conditions are within the specifications of this filter system.