One of the reasons why it is possible to drink too much water is because your kidneys can only filter so much fluid at a time. If your kidneys are healthy, you can filter about 800 to 1,000 mL or 0.21 to 0.26 gallons of water, meaning you can drink about this much every hour and have your kidneys function normally…
When considering how much water healthy kidneys can filter in a day, you can filter about 15 L — almost 60 glasses — of water each day,” – Read the full article here:
The point is that your kidneys can filter a LOT of water on a daily basis, but you still have to space out your water drinking and drink a reasonable amount that works for you.
NOTE: If there is any reason why you should not increase your water intake due to kidney issues, an ailment or a chronic illness, do not participate in this challenge. When in doubt, speak with your doctor.