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Reverse Osmosis (RO) water filter systems and twin under-sink filter systems are both mains-fed water filtration systems designed to remove harmful contaminants from your drinking water.
Here are some of the key differences between the two types of water filtration processes.
Filtration Process
Under Sink Filter Systems like the W2W Twin Filter System use carbon and sediment filters to reduce impurities and remove contaminants.
Reverse Osmosis (RO) is a water purification process that uses sediment and carbon filters before and after water is forced through a semi-permeable membrane to remove ions, molecules, and particles.
Some RO and under-sink filter systems – like the W2W Maxiflow Reverse Osmosis System, W2W Maxiflow Filter System and W2W Mixerflow Under Sink Filter System – use a space-saving, single combined sediment and carbon filter.
Efficiency
Reverse Osmosis (RO) systems are known for their high efficiency in removing up to 99% of all contaminants, including calcium, bacteria, metals, viruses, minerals, and chemicals like PFAS, “forever chemicals.”
RO systems offer the most reliable water filtration process if the local water supply comes from bores, tanks and well water, which is more vulnerable to harmful cysts, viruses and bacteria.
Twin Filter Systems are also highly effective at removing harmful contaminants, chemicals (including PFAS) and bacteria and are the most popular choice for households connected to a reliable municipal mains water supply.
They are also widely used to address specific contaminants and deficiencies in the local water supply and are easily combined with alkalising, mineralising and metal reduction filters to improve the quality of drinking water in homes.
The RO filtration process is slower than the Twin System process, so check that you are investing in a system that can meet your household water needs.
Mineral Retention
Reverse Osmosis removes just about everything out of source water, including some of the healthy minerals we need.
Twin Water Filter Systems leave healthy minerals in filtered water.
With both methods of filtration, it is simple to incorporate additional remineralising and specialist water treatment filters to address specific deficiencies.
Waste Water
One of the main disadvantages of Reverse Osmosis is that up to 3 litres of water may be discarded for every litre of purified water produced.
Wastewater goes down the drain, although you can collect it to use in the garden and for doing the laundry.
Twin Filter Systems don’t waste water to make water.
Installation and Maintenance
Reverse Osmosis Filter Systems and Twin Water Filter Systems both need to be connected to the mains water supply under the sink.
The process for installing RO and Twin Filter systems is similar and should be carried out by a professional plumber or water filtration technician.
View Water2water’s Installation Service.
Carbon and sediment filters used in both types of filter systems need to be replaced regularly and at least every 6 to 12 months, to maintain the quality of drinking water.
The actual frequency will depend on the quality of your source water and how much water passes through the system daily.
The delicate semi-permeable membrane in RO systems is designed to last up to 4 years, and its lifespan will depend on the quality of the source water and regular replacement of the sediment and carbon filters in the system.
Most RO systems come with a pressurised water tank to store purified water until you need it, and this should be sanitised and serviced regularly and re-pressurised if necessary.
All water filtration systems should be serviced and sanitised at least once a year to protect against contaminants entering water pipes and filters.
For customers in Western Australia, Water2water offers regular filter replacement and servicing, and many of our rental plans include scheduled servicing and maintenance and regular filter replacement.
Size
RO systems take up more space under the sink than Twin Filter systems, especially if your RO system has a pressurised tank to store the filtered water.
Compact, space-saving versions of both water filter systems are available, and you can find details at the bottom of this article.
These include single water filter systems and RO systems, which don’t need a pressurised water storage tank.
Cost
Twin Under Sink Filter Systems are normally more cost-effective than Reverse Osmosis filter systems due to the inclusion of the additional filter and the semi-permeable membrane on RO systems, plus the storage tank.
Yearly maintenance and servicing costs are slightly different, and the RO membrane needs to be replaced approximately every 4 years, in addition to regularly replacing the sediment and carbon filters in both systems.
Conclusion
Reverse Osmosis Water Filter Systems and Twin Filter Systems are both highly effective ways to purify your drinking water.
RO systems offer a higher level of filtration and are particularly effective in remote areas with high calcium content and poor-quality source water, as they will remove the calcium and all chemicals from the water.
Twin Water Filter Systems tend to be less expensive and provide great quality drinking water for most households connected to a well-maintained municipal water supply.
Ultimately, the best water filtration system for you and your family depends on the quality of the water coming into your home and how much water you use.
Want some help?
At Water2water, we are always happy to help our customers choose the most cost-effective and reliable water filter system for their homes and families.
Call our friendly team on 1300 880 303 for free, unbiased advice, and we’ll explain how our water filter systems work and give you all the information you need to make the right choice for you.
W2W 4-Stage Reverse Osmosis Filter System
W2W Maxiflow Reverse Osmosis System – uses a single combination sediment and carbon filter alongside the RO membrane
W2W Manual 4-Stage Reverse Osmosis System – dispenses water directly from a hose with no need for a pressurised water tank
View all Water2water Reverse Osmosis Systems
W2W Twin Heavy Metal Reduction Water Filter System – our best-selling home filtration system with the option of a heavy metal reduction filter that will remove contaminants and up to 99% of copper, lead and mercury from your water
W2W Maxiflow Filter System – space-saving system with a single combined sediment and carbon filter
W2W Mixerflow Filter System – connects to your existing mixer tap
View all mains-fed, under sink water filtration systems
About Water2water
Water2water is a privately owned company, and we have been selling, installing, and servicing water filtration systems and filtered water dispensers in Australia for over 25 years.
Our client base includes individual domestic customers, hospitals, factories, government offices and large mining corporations, and we pride ourselves on providing a professional, courteous and responsive service at all times.
Unbeatable Servicing and Maintenance in Western Australia
From our Head Office in Perth and servicing centres in Western Australia, we provide an unbeatable installation, servicing, maintenance and repair service throughout WA.
Our great value servicing and maintenance plans include regular filter replacement and system sanitisation.
Call our friendly team on 1300 880 303 for free, unbiased advice.