I like Hopinso's suggestion... go to the 8 days and then decide. I understand that for chronic conditions it is better to go for long periods of time. 8 or 10 days is good, but if your dad could go longer it would be even more beneficial. Or at the end of the set time period you could switch to a different cleanse, such as juice fasting, or a raw diet for a period, etc. Lots of people end with a Liver Flush, that's a great idea. Keep in contact with the people in this forum, that will really help you stay motivated. Best wishes!