yeah 4.5 hours is a stretch but GH but if you have a baseline to compare to and you do it the same time everytime then it doesnt matter what your numbers are really. Example, I got 23 on some yellows at 3 hours a year ago. Got blacks and getting 31 so i can compare the quality. So if he gets 13 at 4.5 hours and then runs greens and tests them at the same time and gets a 12 then he knows they are close, where if the greens get him a 20 then he knows which is by far superior.