Using ingredients easily available in your kitchen, you can get rid of hardwater stains from your basin.
Mix equal parts of vinegar and water to create a cleansing solution. Apply it to the stained area with a sponge and let it sit for 15-20 minutes.
Wipe the stained surface with a scrubber in a circular motion. Rinse the basin thoroughly.
With baking soda
Sprinkle baking soda liberally on the stained surface. The basin should only be slightly damp.
Scrub the area with a damp sponge. It should form small clumps that take the dirt along with them. Let it sit for a while.
Rinse the basin thoroughly and scrub the surface with a clean sponge for best results.
Using either of the two techniques, you should be able to clean those silly yellow stains and have a neat, clean and shiny basin.