Yup! (I assume you have a 21 oz water bottle?) Can you see how your drinking only 24 oz a day may have caused you to get dehydrated?
There is a chance that 64oz is too much for you - you'll probably know because you'll start feeling bloated and peeing all the time. If that becomes the case, don't force water down just to hit 3 water bottles.
Also, don't drink 64 oz of water AND tea AND soda AND powerade, etc. 64 oz is the total fluid intake.
Anyway - I'm headed out of town so won't be online for at least a few days. Good luck!! You can do this.