julirudi

Hi all, I need help / solution on how to get rid of the white patches on a black solid surface. Pls help me anyone....

Hi All, I need help..have renovated the toilet for like 4 months now....but im facing these problems with my toilet tiles which is black for the wall tile and black homogenious for the floor tile..theres always this white stain( people tell me its calcium) be it at the dge of the tile or anywhere..i've tried scrubbing, spraying water etc but after a while when its dry..the stain will be there again..how can i remove this?? Pls help...