Pretty easy question. In the last two months I've found myself drinking a lot of water and it's really been helping me. I don't get as tired and have pretty much gotten rid of all those mild dehydration headaches I would get. I take a 600 ml bottle of water with me to uni and go through about 3 bottles of it in a day. So overall I'd say I drink around 2 litres (that's about 0.44 gallons) a day. What about you?