Hi
It is a myth that change in water is directly related with appearance of pimples. Pimples occur due to hormonal changes during adolescence.
Testosterone hormone leads to hyperactivity of oil glands which clogs skin pores finally leading to pimples. Pimples can increase due to stress or with junk food and dairy products. Keep your face off dirt and oily by washing 2-3 times daily. Consult a qualified dermatologist who will prescribe medicines to keep your acne under control. Hope this helps.
Regards
Dr Vijay Adhe,
Eternis Skin & Hair Clinic,
Pune.
www.eternisclinic.com