How do i remove calcium build up due to bore water?

the house that i live in has bore water.the shower tiles has white calcium build up all over and no matter what i use it wont come off.iv used bi carb soda,white vinegar,shower power,ajax,straight bleach but nothing work.i guess it doesnt help that to rinse it i have to use bore water.but i tried towel drying it aswell but to no avail