Water stains accumulate on countertops when water is left to stand, at which time it dries into and stains the surface. This is especially present in porous surfaces such as granite. To remove the water stains, you must use mild ingredients that will safely take off the water stains without causing damage to the granite. There are a few commercial stain removal products designed for use on granite, but these are expensive and typically not to hand when you need to remove a stain. Instead, make a stain removal poultice from basic household items.
Pour powdered baking soda into a bowl. You can buy baking soda from most supermarkets, grocery and home improvement shops. Use enough powder to cover the stain.
Stir hydrogen peroxide into the bowl, mixing until you have developed a thick, creamy paste.
Spread a thick layer of this paste, or poultice as it is sometimes called, over the stain. Cover the entire stain with a 1 cm thick layer of this poultice.
Tear off a piece of cling film that will cover the paste. Poke 10 small holes into the cling film.
Place the piece of cling film over the poultice.
Allow the poultice to dry fully, and scrub the poultice off with a wet cloth. All water stains should now be removed. Repeat the stain removal procedure if all water stains are not removed with the first application.