Usually you know you are pretty damn close when you see that first vien appear in your lower abes. If you are using a ckd you should be able to evaluate how you look at the end of your carb-up every week. As you get closer to contest condition start playing with the types, and amounts of carbs you use to carb up, along with your sodium intake to see how it effects your water weight. Also, you make want to make a trial run with your diuretics during your carb up to see if you look pretty close when dry. Don't know if my info was helpful..you didn't give us many details.