Do You Need to Remineralize RO Water?

Remineralizing RO water is not required for safety.
But safe and optimal are not the same thing.
When Remineralization Makes Sense
The most immediate reason most people remineralize RO water is taste.
does ro remove calcium and magnesium from water  is the most practical argument for doing it.
remineralization after ro before tankless heater  of demineralized water is not definitively harmful, but the WHO guidance exists because the research on chronic low mineral intake warrants a practical minimum.
Knowing which category your household falls into helps calibrate how urgently remineralization is worth addressing.
Reasons to Skip It
Adding minerals is an improvement, not a correction of a deficiency that affects everyone equally.
Cost and maintenance are also legitimate reasons to hesitate.
If the maintenance burden of any of those methods feels like more effort than the benefit justifies, it is a reasonable position to skip remineralization entirely and drink the water as it comes out of the system.
When  how to remineralize drinking water  Gets Stronger
Athletes or high-volume drinkers consuming three or more litres of RO water per day are replacing more electrolytes with demineralized water and benefit more from remineralization.
One group that should proceed carefully: anyone on a sodium-restricted diet or with a health condition affected by mineral intake should check with a healthcare professional before adding any mineral supplement, since some formulations use mineral salts that contribute sodium.
Should You or Shouldn't You
If you have children drinking primarily RO water, remineralize.
If none of those apply, the water is fine as it is.