Quick answer
Because RO removes minerals from water, some believe it can also remove minerals from the body. This concern stems from a misunderstanding of how we get our nutrients.
Water is mainly for hydration. Food is for mineral intake. Since most of the essential minerals we consume come from our food, drinking RO water is generally considered healthy for those with a healthy and balanced diet.
What RO actually does to minerals, TDS and pH
RO reduces total dissolved solids (TDS), heavy metals, salts, minerals, and more. RO water typically has a lower pH because of this. However, pH in a glass is not the same as body pH. Through the process of homeostasis, the human body uses its independent and highly efficient mechanisms to regulate its own pH. Therefore, the lack of minerals in RO should not noticeably affect a healthy individual’s nutritional intake.
Does RO remove all minerals?
RO removes nearly all dissolved substances from water. This includes beneficial minerals like calcium, magnesium, potassium and sodium. and contaminants such as bacteria, lead and nitrates.
Always check the system’s specs and certifications, as exact reduction levels depend on the membrane and system design.
Is low-TDS water ‘aggressive’ or ‘hungry’?
It’s true that low TDS water can be both hungry for minerals and corrosive, or aggressive. Water with very low TDS (0–50 ppm) has a high capacity to absorb substances from pipes and plumbing fixtures. This leaching of minerals can make the water corrosive. In terms of drinking, the main concern is taste and preference.
Do you need minerals in your water to be healthy?
For most people, water isn’t typically their main mineral source. The minerals in water should complement an already balanced diet, not replace it as the primary source of essential minerals. As mentioned earlier, very low-mineral water can lead to ‘aggressiveness’ issues in some contexts.
Healthy minerals can affect the taste of the water and RO removes most of these minerals. Because of this, RO can taste cleaner and more preferable to some and more bland and tasteless to others. If you’re worried about your mineral intake or have a pre-existing medical condition, it’s best to talk to your medical provider for further guidance.
The practical takeaway (for most Australian homes)
RO can remove total dissolved solids (by up to 99%, depending on the system), chlorine, and metallic or salty tastes from the water. Remineralisation is an option that can re-add healthy minerals, such as magnesium and calcium, back into your RO water.
The bottom line is this: If your RO tastes fine and you regularly have a normal, healthy diet, you should not need remin. If the RO water tastes flat to you or affects the taste of your coffee and tea, remin definitely helps bring back the flavour.
When remineralising RO water is worth it
Remineralisation is popular because it improves the water's pH balance and results in a more rounded flavour that some may find lacking in purer RO water. Remin may be worth it for you if:
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RO water tastes flat to you
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your children prefer the taste of mineralised water
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you’re a coffee, espresso, or tea enthusiast
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you are worried about corrosion
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you are blending RO with other water
Coffee and tea: why a little calcium/magnesium can taste better
Minerals in the water are necessary for a balanced flavour profile. Pure RO water can lack taste and negatively affect mouthfeel for some. Healthy minerals add a crisp, refreshing taste that’s noticeable in tea and coffee.
Water is the solvent that must pull flavours out of the grounds or leaves. Minerals like calcium and magnesium are essential for pulling the best flavours out of coffee beans and tea leaves. Speciality coffee often targets a modest mineral range.
Alkalinity acts as a buffer and prevents the natural acids in coffee and tea from becoming sharp or sour. Without them, your morning cuppa might taste thin or metallic. Slightly higher buffering stops water from becoming too acidic and protects tea's natural notes.
How to remineralise RO water (best options)
The best methods for remineralising RO water are:
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Inline remineralising cartridges: add to your existing RO line to automatically dose the RO water with calcium and magnesium as it flows to your tap.
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RO system with a built-in remin stage: alkaline or 6-stage models include a mineral stage that balances pH and improves taste straight away.
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Mineral drops: manually add concentrated liquid minerals to your glass or pitcher.
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Blending: involves mixing a small amount of filtered or mineral water back into your RO water yourself.
Remineralisation cartridge
An inline remineralisation cartridge is the most common upgrade for under-sink RO systems. As water passes through the media, which is typically crushed calcium carbonate and magnesium, it dissolves a small amount of these minerals back into the stream. You’ll immediately notice a more refreshing taste that resembles spring water.
Replacement intervals will vary depending on the cartridge. Most cartridges need to be swapped every 6-12 months to maintain consistent mineral levels.
Where should the cartridge go for best results?
Remineralisation cartridges are often best placed where the flow is slowest. This is typically between the membrane and the storage tank. It’s recommended to place your cartridge here because it provides the best possible extraction, so you get the most minerals back in the water. Remember, the more contact time your system has with the cartridge, the better mineral pickup you’ll have. If you have any questions or feel unsure, don’t hesitate to hire a plumber to figure it out for you.
Reverse osmosis remineralisation: our recommendation (final takeaway)
Choosing whether or not to remineralise depends on personal preference and how you use your water. If you dislike the flat taste and want the best possible water for drinking, tea, and coffee, then choose an RO system with an integrated remineralisation stage (i.e. 6-stage) or add a post-filter cartridge. If you prefer an ultra-clean taste, you can skip this step entirely.
Are you looking to add Reverse Osmosis or remineralisation to your home water network? MDC Water brings over 30 years of experience in water and wastewater treatment. Explore our range of RO systems today and contact us when you’re ready to upgrade your water system.
FAQs
What happens if you don’t remineralise RO water?
If you choose not to remin your RO water, it will mostly only affect the taste. Non-remineralised RO water is known to taste flatter, which some people prefer.
Is it bad to drink RO water without minerals?
Not inherently, for healthy individuals with balanced diets. However, it can affect pH and may require mineral intake from food to prevent deficiencies in individuals with poor diets.
Do I need to add electrolytes to reverse osmosis water?
In most cases, you don't have to unless advised by a health professional. RO water is usually safe to drink on its own. Remin is mostly down to taste and personal preference.
Is RO safe for the kidneys?
RO water is generally considered safe and also beneficial for the kidneys because it removes harmful contaminants and heavy metals. This is especially true for those with kidney issues or in hard water areas. If you have kidney disease, be sure to consult with your GP first.
How to naturally remineralise RO water?
You can restore balance using mineral drops or a remineralisation filter. These methods safely reintroduce essential calcium and magnesium. You should avoid the baking soda hacks that are available online, as they often result in a salty taste and unpredictable pH levels.
What is the best mineral supplement to add to RO water?
You should look for calcium and magnesium-focused remin products and avoid overdoing the dosage.
