Yep...'in ounces'...not half your weight...but this is the recommendation for your daily water intake ALL the time...not when doing the p&b colon cleanse. When you take the p&b shakes you have to drink even more water because psyllium is a soluble fiber that absorbs like crazy! You mix each shake with 8-10oz of water and then follow it with another 8-10...and that's on top of your daily water intake.
It's also recommended that you use liquid minerals including trace minerals on a regular basis in order to ensure good electrolyte balance, mineral reserves and an alkalinized system...also use unrefined Sea Salt .