Search this question and you will find two extremes. One says RO water is dangerous and leaches minerals from your body. The other says minerals in water are irrelevant because you get them from food. Neither is quite right, and the honest answer sits in between.

What RO water actually is

RO water is water with almost everything dissolved in it removed. That includes the contaminants you wanted gone, and the calcium, magnesium and potassium that were dissolved alongside them. The result is safe, clean and close to empty.

The overstated argument

You will see claims that demineralised water "pulls" minerals out of the body. This gets repeated a great deal online, usually without a source attached. Treat it with scepticism. Your body regulates mineral balance through diet and kidney function, and a glass of low-mineral water is not a meaningful threat to that.

We would rather not sell a product on a fear that does not hold up.

The understated argument

The opposite position — that water minerals are irrelevant — misses two things.

First, taste. Dissolved minerals are what give water body and flavour. Their absence is why RO water tastes flat, and flat water is water people drink less of. If a purifier quietly reduces how much your household drinks, that matters more than any mineral figure.

Second, quantity. Water is not a marginal part of the diet. Several litres a day, every day, is a meaningful volume, and small contributions across a large volume are not nothing. Water is a modest mineral source in most diets, not a zero one.

So: do you need to?

You do not need to remineralise in the sense that you will come to harm otherwise. But if RO is your household's main drinking water, restoring minerals is a small, cheap change that improves the taste and puts back something the purifier removed for reasons unrelated to your health.

That is the whole case. It does not need to be more dramatic than that.

How to do it

The practical options are a mineral cartridge, an alkaline filter, or concentrated mineral drops. Our guide to RO water remineralisation compares all three.