for the dark spots of pimples, use shwabe's Silicea pentarkan medicine daily twice.It will help for both pimple n scar marks also.Along with that, U can use calc. sulph 6x daily 5 tablets daily twice.... will give good result. Apply daily mint[pudheena]t leaves paste with Lemon juice twice n keep for 1 hr, then wash with normal water. Take more water daily, minimum 3-4 ltr is required for maintaining healthy skin health. Aloevera gel application also helps.