CD recommeneds at least 2 25 ltrs per day, LL I think is 4 ltrs.
On these diets water is the key, I was on CD and had 4 ltrs per day.
Water helps weight loss, stops the hunger pangs and also is a key to keep healthy on VLCD.
As you move up the stages then you can decrease your intake, however, I still have 2 ltrs per day, or at the very least he reccommended 8 glasses.
Hope this helps!!