Many five-stage systems also include a mineralization cartridge as an optional sixth stage, which adds back tiny, healthy minerals like calcium and magnesium. Why? Reverse osmosis is so thorough it removes the good stuff too.
Ever heard the rumor that RO water “leaches minerals from your body”? It’s mostly bunk—but adding minerals makes it taste smoother and less flat. Your coffee will thank you. (And your tea won’t look sad and grayish.)
