Actually may sense yan for those who dont know the difference between water and h2O. Well kung sino man ang naglagay niyan he/she is not educated, or unaware. This explain of that,
Water, in it's natural state will contain impurities, it's mostly a mixture of H2O and dissolved mineral salts like calcium bicarbonate and magnesium bicarbonate.
H2O is pure, it contains no mineral salts or other substances. Pure water is never found in nature. It must be produced using distillation or reverse osmosis.
So malamang ginamitan ng purification distillation etc. or substance na masala at maging h2O na in nature siya.