Reverse osmosis water is water that has been pushed through a semi-permeable membrane that rejects most dissolved substances, which is why it is so effective and why the mineral question comes up at all. The membrane does not distinguish between a contaminant and a mineral: both are dissolved, so both are largely removed. That single property explains the benefits people buy it for and the objection they read about online.
What the membrane actually takes out
A reverse osmosis membrane rejects dissolved ions broadly, which means it reduces a very wide range of contaminants in one step rather than needing a separate media for each. That is unusual in water treatment and it is the reason reverse osmosis is the default recommendation when a household has a specific dissolved contaminant to deal with and wants one system at the drinking tap rather than a shelf of specialized cartridges. Because it works on size and charge rather than chemistry, it does not need to be told what it is removing. The concentrate stream carries the rejected material to the drain, which is why the system uses more water than it delivers.
The mineral question, handled honestly
Since the membrane rejects dissolved substances indiscriminately, reverse osmosis water is low in calcium and magnesium as well as in whatever you were trying to remove. For most people, food rather than drinking water is the main dietary source of those minerals, and plenty of households drink reverse osmosis water without giving it any thought. We do not give medical advice, and anyone with a specific health condition or dietary concern should raise it with their doctor rather than with a water treatment supplier. If you would prefer some mineral content back, remineralization cartridges are a standard, inexpensive add-on stage that reintroduces calcium and magnesium after the membrane.
Taste, pH and what it does in the kitchen
Reverse osmosis water tastes clean and slightly flat to people used to mineral-rich tap water, because the taste of water largely comes from what is dissolved in it. It also tends to be slightly acidic, since removing alkalinity leaves dissolved carbon dioxide to dominate, and a remineralization stage lifts both the taste and the pH back up. In practical kitchen terms it makes noticeably better tea and coffee for most palates, leaves no scale in a kettle or espresso machine, and gives clear ice. Cooks who have moved from very hard water usually notice the difference in coffee before they notice anything else.
When reverse osmosis is clearly the right call
The strongest case is a specific dissolved contaminant that other household treatment does not touch, or several of them at once, where one system at the kitchen tap solves the lot. Decide that from evidence rather than from worry: the EPA requires every community water system to publish an annual Consumer Confidence Report and maintains a finder for them, so a utility customer can read what is measured in their supply before spending anything, while a well owner needs a laboratory test since nobody else is sampling that water. Our best reverse osmosis water filter comparison covers which systems carry certified performance claims for the contaminants people most often want removed.
Questions people ask about is reverse osmosis water good for you
Does reverse osmosis remove healthy minerals from water?
It removes dissolved minerals along with dissolved contaminants, since the membrane does not distinguish between them. A remineralization cartridge is a standard optional stage if you want some added back.
Why does reverse osmosis water taste flat?
Taste in water comes largely from dissolved minerals, and the membrane removes most of them. A remineralization stage restores some mineral content and the fuller taste that comes with it.
Is reverse osmosis water acidic?
It tends to be slightly acidic, because removing alkalinity leaves dissolved carbon dioxide with more influence on the pH. A remineralization cartridge raises it back toward neutral.
Should I install reverse osmosis if my tap water is already fine?
Check your utility's annual water quality report or test a well first. Reverse osmosis is most worth it when there is a specific dissolved contaminant, or several, that you want reduced at one tap.