I drink between 1 and 2 gallons per day. The color of a person's urine is a good indicator of dehydration. As protein intake increases, so does the necessity for increased water consumption.
Although sports drinks have proven more effecient at hydrating an athlete than plain H2O, there is nothing more efficient at detoxification and cleansing the system especially the kidneys than plain water. Juice and soft drinks are full of empty calories, and bottled juice is void of most nutrients and enzymes as are most processed foods. I use spring water for the trace minerals, but tap water is fine. Except for my morning coffee and an occasional cup of green tea, I drink nothing but water.
I start the day by gulping down a 24 oz glass of hot water to clean and flush the bladder and start hydrating my system. I drink at least 10 oz water before every protein meal and mix my protein powders with 50 gm protein and 18 oz water.
It is best to drink water before your protein meal so the stomach is hydrated and ready for the digestion process to begin. Deeply colored urine is the quickest sign of dehydration, and barring the bright yellow color of vit B-6, urine should be nearly colorless if you have enough fluids in your system. Drink water all throughout the day and don't wait until real thirst sets in, as dehydration begins before the warning sign of thirst.
Everyone should read the little book,
Your Body's Many Cries for Water: You Are Not Sick, You Are Thirsty
by F. Batmanghelidj M.D.
http://www.amazon.com/gp/reader/0962994251/ref=sib_dp_pt/002-1998181-3780851#reader-link
"One man's solution to soaring health costs: water."
- Paul Harvey