We recommend having approximately 4-5 glasses of juice per day. 

If you are sedentary throughout the day, which means you are not active / doing too much physical activity during the juice fast, 4-5 glasses of juices will be sufficient.

If you are doing exercises / physical activity during the fast, you may drink upto 5-6 glasses of juice per day.

However, the best rule to follow is - drink the juice whenever you feel hungry :)