Depends on your individual thirst I suppose. I used 76 oz. of juice a day divied into three meals. I drank plenty of water as well. I found that cutting back on the maple syrup made me feel hungrier so once I put in the recommended amount I was more comfortable.
It sounds like you may be a little short on your water. Plain water will help maximize the detox, and half your weight in ounces is the recommended goal. Dry skin-brushing will help with detox. Epsom Salt baths will help with detox. Tongue brushing will help with detox. Moderate exercise, even if just walking, will help with detox. Those probably would be the most basic extra practises to help maximize the fast. Others might suggest enemas if you feel like you are detoxing fast and feeling spacey or colon therapy if you have access to a good hydro-therapist.