Reverse Osmosis Explained: Is an RO System Right for Your Kitchen?

Reverse osmosis, often shortened to RO, comes up a lot in conversations about drinking water quality, but it is not always clear what makes it different from a standard carbon filter.

How Reverse Osmosis Works

An RO system pushes water through a semi-permeable membrane with pores fine enough to block dissolved solids, many chemical contaminants, and microorganisms that carbon filtration alone will not remove. Most home systems combine this membrane stage with sediment and carbon pre-filters, so the water passes through several stages before it reaches the tap.

Why People Choose RO Water

The appeal of reverse osmosis is thoroughness. Because the membrane filters at such a fine level, RO water tends to taste noticeably cleaner and is popular with households who want the highest practical standard of drinking water at home, particularly for families with young children or anyone who prefers to avoid dissolved chemical residues.

What to Know Before Installing One

RO systems do produce some wastewater as part of the filtration process, and they typically require a dedicated tap or a storage tank since filtration through the membrane is slower than a standard mains flow. Cartridges and membranes also need replacing on a schedule to keep performance consistent, so ongoing maintenance is part of the deal.

RO vs Whole House Filtration

Reverse osmosis is almost always installed as a point-of-use system, most commonly under the kitchen sink, rather than treating the whole house. It is best thought of as a drinking water solution rather than a replacement for whole house sediment or chlorine filtration.

Is It Right for You?

If your priority is the cleanest possible glass of drinking water and you are comfortable with a dedicated tap and periodic cartridge changes, reverse osmosis is worth considering. If you are mainly concerned about general household water quality, it may make more sense alongside, rather than instead of, a whole house filter.

Certification Standards Specific to Reverse Osmosis

Reverse osmosis systems are tested and certified under NSF/ANSI/CAN 58, a standard specifically for RO systems, which is distinct from NSF/ANSI 53 used for carbon-based contaminant reduction. When comparing RO units, checking which standard a system is certified against tells you more than a general “certified” label. RO membranes are also one of the most effective methods for reducing PFAS (“forever chemical”) compounds, alongside dedicated PFAS-focused stages like AquaCo’s Disruptor® technology used in the whole-house systems we supply.

Verifying Certification for Systems We Supply

Any component that connects to Victorian mains plumbing must also carry Australian WaterMark certification, separate from the US-based NSF standards. You can check our supplier AquaCo’s WaterMark licence (No. 23448) on the WaterMark public register, and their filtration listings on the NSF certified product database, before you decide on a system.