Hello gunnerrat
I would be inclined to agree with jaymz's post in this thread.
As long as the recommended pre-fast diet consists of high-water content food, then much water during the fast is not needed anyway.
Your body is a reliable indicator for what it needs: rest/sleep when tired; eat when you are hungry; exercise when your body calls for it.....if you do not exercise, then stretching of all the body limbs and muscles is naturally induced.
In the same way your body will call for fluids when needed and the danger of dehydration is avoided, but the symptoms of this in adults are:
dizziness, headache, dark urine (may have a strong odor), inability to urinate, dry mouth and nose, weakness, nausea and vomiting, which are mostly the symptoms of detox anyway.
Drinking according to thirst has always been the most reliable indicator during a fast by all of the qualified and professional protagonists of fasting both in the past and in the present.................
Dr H M Shelton...........
"Fasting animals take but little water and some of them none at all. For example, the Alaskan fur-seal bull takes no water throughout the whole of his four or five months fast. Hibernating and estivating animals do not drink water during their period of dormancy. It is the rule that sick animals (this is especially true of the acutely sick and seriously wounded animals) will not drink much water. I have repeatedly seen sick animals take no water at all for days at a time, or take but a few sips once or twice a day. For the most part, they refuse to drink large amounts of water.
Thirst is seldom great during a fast. I have watched fasters go for two and three days at a time and take no water, simply because there was no demand for water, and they have not suffered as a consequence. Others take but little water; sometimes not more than half a glass a day. Then, there are those who drink much water. In some of these there may be thirst; in others it appears to be nothing more than a result of a desire to get something into the stomach. Others drink because they have been taught that they must. In occasional fasters, there will arise a great thirst that may last a day or two or three days, during which time they will drink so much water that their tissues become water-logged and they gain in weight as a result. The thirst subsides and they do not drink so much thereafter. Large quantities of water should be taken when thirst calls for much water, as it sometimes does; otherwise, there should be no effort made to take large amounts of water. Excesses of water are simply eliminated without increasing the elimination of waste--perhaps, on the contrary, with an actual decreased elimination of waste."
http://www.soilandhealth.org/02/0201hyglibcat/020127shelton.III/020127.ch29.htm
Regards
Chrisb1.