Pressure and density relationship

Considering that the pressure-density relationship for substances with constant density can be defined as P=rgh, where r=density of the substance, g=acceleration of gravity, h=height/depth of the substance, what would be the required height (length) for the tube in a glass-tube barometer if we use water instead of mercury? The density of mercury is 13593 Kg m-3 and the density of water is 1000 Kg m-3 (please, show your reasoning and calculations).