Fasting for Weight Loss - how much weight did YOU lose? (looking for experience posts!)

Hi everyone! I'm starting a Water Fast today and I plan to continue it until I lose 20 pounds. I'm thinking Water Fasting for a week and then integrating gatorade to get my electrolytes back. It really depends though on how soon I feel that I need those electrolytes, etc. The only exercise I'm doing right now is walking to class.

How long will it take me to lose 20 pounds on a water fast? Thanks!