Cleaning compositions containing water soluble magnesium compounds and methods of using them

A method of cleaning a hard surface comprising:

• contacting the hard surface with an aqueous composition comprising water comprising a calcium ion, a water soluble magnesium salt, at least about 5 wt % to less than about 60 wt % of a source of alkalinity, and about 0 wt % to about 20 wt % surfactant, wherein the aqueous composition during contacting comprises magnesium ion in a molar amount equal to or in excess over a molar amount of said calcium ion, and wherein the composition is substantially free of a builder and a phosphate or phosphate containing compound;
• and
• achieving said hard surface with an acceptable amount of hard water spotting, wherein the acceptable amount of hard water spotting comprises up to about one quarter of the surface containing spots.