Does Reverse Osmosis Remove Minerals?
Yes — RO strips almost everything, including the beneficial calcium and magnesium. That's why RO water has very low TDS and can taste flat or slightly acidic. It's a taste effect, not a danger for anyone eating a normal diet. If you like mineral taste or want the pH raised, choose a system with a remineralization (alkaline) stage — just remember it's one more cartridge to replace on schedule.
The one thing to know: Reverse osmosis strips almost everything from water — including the beneficial calcium and magnesium — which is why RO water can taste flat or slightly acidic. That's cosmetic, not dangerous, but it's why many systems add a remineralization (alkaline) stage that puts minerals back and raises pH for taste. If you like mineral-tasting water, look for a remin stage; just know it's an extra cartridge to replace on schedule.
Why RO water tastes "flat"
Taste in water comes largely from dissolved minerals. Because RO removes them down to a very low TDS, the result can taste flat or slightly tart, with a pH a bit below neutral. Many people don't mind it; others notice immediately. Neither reaction is wrong — it's preference, and it's the single most common complaint about otherwise-excellent RO systems.
What a remineralization stage adds
A remin (alkaline) cartridge sits after the membrane and reintroduces a small, controlled amount of calcium and magnesium, nudging pH back toward neutral and restoring a rounder taste. It does not undo the filtration — the contaminants the membrane rejected are already gone. The trade-offs: it's an extra recurring cartridge, and cheap versions can shed a little mineral dust into the first draw and slightly raise a TDS reading.
This page is general taste-and-spec information, not medical or nutritional advice.
Frequently Asked Questions
Yes. RO strips nearly everything dissolved in the water, including beneficial calcium and magnesium along with contaminants. That's why RO water has very low TDS and can taste flat or slightly acidic compared to mineral-rich tap water.
For people eating a normal diet, the minerals in drinking water are a small fraction of total intake, so removing them isn't a health problem in itself. The main effects are taste (flat) and slightly lower pH. If you prefer mineral taste or want the pH raised, a remineralization stage handles it. We report this as taste/spec information, not medical advice.
A post-membrane cartridge — usually calcite (calcium carbonate) or a mineral blend — that adds a small amount of calcium and magnesium back into the RO water, raising pH toward neutral and restoring a fuller taste. Many premium RO systems include or offer one.
It's a taste-and-preference choice, not a safety requirement. If flat RO water bothers you or you want a higher pH, choose a system with a remin stage. Just know it's an extra cartridge to replace on schedule, and cheap alkaline cartridges can shed fine mineral dust into the first draw and nudge TDS readings up.
No. It adds back only a controlled amount of calcium/magnesium for taste and pH after the membrane has already removed contaminants — it doesn't reintroduce the lead, PFAS, or other contaminants the RO stage rejected.