When you think they have stopped growing, wait another week. Then chop. Seems to work good for me. Also, if they have been budding for six weeks, that is the time the quickest indica's will finish. Usually they are more close to 8, so probably 7 would be safe. But like other's suggested, the microscope way is the most scienfific and will give you the most accurate results. Good luck and post some pic's!

TGT