> there are additives which AIUI prevent or at least significantly reduce leaching Hard water (high in calcium and magnesium) can form a scale on the inside of

> there are additives which AIUI prevent or at least significantly reduce leaching Hard water (high in calcium and magnesium) can form a scale on the inside of copper pipes. In a way this acts as a protective layer, as the water doesn't actually come into contact with the copper.