Answer:
It really depends how well you stay hydrated. Sodium (salt) that you take in keeps hold of all the water you hold onto when you dont drink enough water in the game so you need 8 eight ounce cups of water a day (if you eat around 1500 calories a day, more if you eat more calories).
Now to know how much weight loss is water weight is hard to do unless you are constantly going to a doctor to determine how much of your body weight is fat. I think the best way to determine how much you lose is water weight is to stick with what you normally do but drink more water and see what happens.
Drink more water. It is very useful to lose weight fast.