Be careful not to drink more than a gallon of water daily. Include any kind of pop, fruit drinks, juices, because those are mostly water anyway.
You should know you are drinking lots because you're peeing so much.
What happens is that each cell receives water to survive, and if it receives too much water, then the cell membrane, which is kinda like skin to hold it all together, can burst. And if too many burst, then you're in trouble. Another problem with drinking too much water is that you can actually flush some of your vitamins and needed nutrients out of your body.
As in everything in life, even water needs balance. The "8 glasses of water" we are supposed to have daily? You need just enough so you aren't feeling thirsty or dry all the time. Weird as it sounds, drinking lots of water actually helps you eliminate excess water in your system, makes you less hungry. You can actually drown your kidneys if you over drink, which you are not doing. Not drinking enough will dehydrate you , and if you are missing enough, you will start getting headaches.
Water also gives you energy !