Wanting to start a water fast

Hi All,
This thread looks very intresting...i need help...and may be u guys can help with your expereince..i am desprate to loose70 lbs ( 30kgs) and i am hoping Water Fast can be the answer to loose the weight quickly....i wanted to ask do u feel very weak when u r on this fast and can one excersice also along with the water fast..and the most important thing..in how much time can i expect to loose 30 kgs of weight while on water fasting..pls help me
Natasha Tweet