My Water Filter's Buyers Guide to Reverse Osmosis Water Filters

In this article, we are going to look at the most popular types of Reverse Osmosis (RO) Water Filters available today. The most important thing to consider when it comes to Reverse Osmosis systems is what it does to the water AFTER the membrane.

RO systems will strip out almost everything, including fluoride, lead, chlorine, chloramine, pesticides, nitrates, sulphates, detergents, and even heavy toxins like PFOS and PFOA.

Before we talk about specific products, it might help to explain briefly how Reverse Osmosis works. Reverse Osmosis differs from traditional water filtration where impurities are just trapped within a cartridge. In an RO system, water is pushed through a highly advanced membrane. The clean water is directed to your tap or holding tank, while the concentrated contaminants are flushed directly down the drain.

Stage 1: Sediment Cartridge
Water from the tap enters the sediment cartridge, which removes larger particles like dirt, rust and silt. This improves the clarity of the water and, most importantly, protects the subsequent carbon filters from clogging.

Stage 2: Carbon Cartridge
This stage eliminates chlorine, chloramine and volatile organic compounds (VOCs). It is crucial for removing bad tastes and odours, and it conditions the water, protecting the delicate RO membrane from chlorine damage.

Stage 3: Reverse Osmosis Membrane
The heart and soul of any RO system. The RO membrane forces water through microscopic pores, splitting it into clean pure water and wastewater. It filters out dissolved inorganic and organic compounds like fluoride, heavy metals and Total Dissolved Solids (TDS).

Stage 4: Post Filtration & Remineralisation
Because the RO membrane strips everything out, the final stage is designed to polish the water's taste and, crucially, add healthy minerals back into the water to balance the pH.

Once the water has undergone the intense reverse osmosis process, we are left with pure, but ACIDIC WATER. The pH of water straight out of an RO membrane is usually around 6. You don’t want to be drinking it just yet!

Drinking water should ideally be at least a neutral 7 pH or higher. Drinking highly acidic water long-term carries the risk of stripping essential minerals from your body as it tries to maintain a healthy internal pH balance.

The main difference between the top-tier systems below is how they remineralise, structure or deliver that water to you.

If you want a permanent, tucked-away solution for your home, under sink systems are the way to go. Here is our line-up, ranked from the absolute best down to our highly reliable standard systems.

1. The Best of the Best: ULTRAPURE Toxic Contaminant Removal Reverse Osmosis Water Filtration System (Triple Housing) 

If you want the ultimate, uncompromised standalone system, this is it. Designed specifically for harsh Australian water conditions, this triple-housing unit handles everything right under your sink—no pre-filtration or whole house water filter required. It utilises a unique 8-stage process, including a Disruptor cartridge and an RO membrane, to target the absolute worst toxins, including PFOS, PFOA, microplastics and heavy metals. After purification, it runs through a remineraliser to elevate the pH to a healthy, mildly alkaline level. Plus, it comes with an automatic leak-stop detector for total peace of mind.

2. Next Best: ULTRAPURE Toxic Contaminant Remover Twin Undersink RO Filter 

This is a phenomenal, high-performance system, but there is a catch: you MUST have a Whole House Water Filter installed prior to using this unit. Because it is a twin-housing system, it relies on your whole house filter to remove the bulk of the sediment and chlorine. This allows the Twin Undersink RO to focus purely on the heavy lifting—removing fluoride, heavy metals and stubborn toxins via its premium RO membrane, before alkalising the water for drinking.

3. Next Best: The HPF 7 Stage Reverse Osmosis Under Sink Water Filter System
Honed over a decade, this 7-stage hydrogen-rich system is designed to produce the perfect alkaline drinking water (pH 8.5 – 9.0) to aid in hydration and recovery. After the traditional RO stages, the water undergoes FAR Infrared treatment, which uses infrared energy to keep the water ultra-fresh. This is paired with negative magnetic treatment to produce increased dissolved oxygen content, leaving you with vibrant, incredibly healthy water.

4. Next Best: HPF 5 Stage Reverse Osmosis Alkaliser
A fantastic mid-tier option for families. This system runs through the standard rigorous RO purification process and finishes with a dedicated alkalising cartridge. As the clean water flows through, it absorbs essential minerals, elevating the pH to a healthy alkaline level and ensuring your water tastes sweet, fresh and smooth.

5. Next Best: HPF 4 Stage Reverse Osmosis Low Alkaline
If you aren't looking for high alkalinity but still want safe, pure water, this 4-stage system is perfect. After the RO membrane strips the contaminants, the water passes through a stabilising remineraliser. It doesn't push the pH to high alkaline levels; instead, it provides just enough calcium and magnesium to stabilise the water at a neutral, healthy ~7.0 pH.

For renters, travellers or anyone who doesn't want to drill a hole in their benchtop, portable RO systems are an incredible solution. We break these down into two main categories.

These are brilliant freestanding water stations. You simply plug them into the wall, fill the raw water tank at the sink and the machine does the rest. No plumbing, no tap diverters.

• Philips Aquaporin Reverse Osmosis Water Station with Compressor Cooling
  This unit is a game-changer. Utilising state-of-the-art Aquaporin RO technology, it filters your water to an incredibly high standard. The best part? It features a built-in compressor, meaning it dispenses beautifully crisp, chilled water on demand. Perfect for hot Australian summers.

• Philips Aquaporin Reverse Osmosis Water Station with Instant Heating
  Sharing the same world-class Aquaporin RO filtration as its sibling, this model swaps the chiller for an instant heating element. At the touch of a button, you can dispense pure, boiling hot water—making it the ultimate benchtop companion for tea, coffee and cooking, all without touching your plumbing.

These classic systems sit neatly on your bench. A small diverter valve attaches to your existing kitchen tap spout. Turn the tap on, and the pure water slowly trickles out of the system's blue hose, which you simply direct into a jug, glass or glass water dispenser.

• MWF RO 4000 Benchtop Reverse Osmosis Water Filter System with American Alkaliser
  Our top-tier traditional benchtop system. It features a high-grade RO membrane that purifies your tap water drop by drop. Before the water hits your jug, it passes through a premium, USA-made alkalising cartridge, ensuring the water is packed with healthy minerals and boasts a high alkaline pH for optimal hydration.

• MWF RO 4000 Benchtop Reverse Osmosis Water Filter System with Standard Alkaline
  Delivering the exact same rigorous RO purification as the American model, this system utilises our standard alkaline cartridge. It is an incredibly cost-effective way to get high-quality, remineralised and pH-balanced RO water straight from your kitchen tap without any permanent plumbing.

To help with your RO water system decision, first work out whether you require an under sink or a benchtop system.

• If you want the absolute ultimate in Under Sink filtration and don't have a whole house filter: We highly recommend the ULTRAPURE Toxic Contaminant Removal Triple RO. It does it all, completely standalone.

• If you already have a Whole House system: The ULTRAPURE Twin Undersink RO is the perfect complementary companion for your kitchen.

• If you want Under Sink water tailored for maximum health and recovery: The HPF 7 Stage with its FAR Infrared and magnetic treatment is phenomenal.

• If you are renting or want a Benchtop System with zero plumbing: Go for the Philips Aquaporin Water Stations. Choose the Cooling model if you love chilled water, or the Heating model if you're a tea and coffee lover.

• If you want a budget-friendly Benchtop System that connects to your tap: The MWF RO 4000 with American Alkaliser will give you outstanding purity and great-tasting alkaline water, collected straight into your own containers.

If you still haven’t decided which option is best for you, please talk to our friendly support team. We’d be delighted to help you find the perfect fit for your home!

Click here to see our full collection of Reverse Osmosis systems.