There is no mistaking the ugly build up of calcium deposits on tile. If you have hard water, you have probably already discovered that calcium deposits build up quickly if untreated and can be difficult to clean. Don't be fooled into thinking you need to buy expensive commercial products to clean your tiles. Try these easy solutions using common household products that will cost mere pennies to make.
Vinegar and Baking Soda
Mix plain baking soda with enough white vinegar to form a smooth paste. This should be wet enough to spread easily, without running.
Cover the problem area with the a thick coat of the baking soda and vinegar paste and allow to soak for 15 minutes.
Scrub with a stiff brush. An old electric toothbrush with firm bristles works great for scrubbing those hard to reach areas. No only does the circular motion of the brush lift and remove calcium deposits, the handle allows you to reach tight areas
Rinse with clear water.