Firstly, not all minerals are good for you. According to the WHO, only calcium and magnesium in water are beneficial to the body.

The other minerals are either not absorbed from water, or are trace minerals like arsenic, lead and aluminium of which the body needs extraordinarily little (less than 100mg/day). In excess, these lead to toxic episodes, heavy metal poisoning and other serious complications.

Secondly, minerals in water are inorganic (like rocks) and not organic (like spinach). You can get your calcium from rocks, or you can get it from dairy, fruit, and vegetables, where the plant or animal has done some of the processing for you. There is considerable debate in the scientific community about the usefulness of inorganic minerals in the human diet. The body can absorb minerals from inorganic sources, but much less efficiently than from organic sources.

Even if the water contains calcium and magnesium, it is not enough to supply in the body’s needs.

You would have to drink more than 30 litres of water a day to get the recommended daily amount of 1000mg of calcium.

And that is provided your body absorbs 100% of the available calcium, which it cannot.

Only exceedingly small amounts of calcium and magnesium are absorbed from the water.

Unfortunately, you do not get to choose: if you leave the beneficial minerals, the harmful ones stay too. It is all or nothing.