I wait until my plants show sex.. A lot of people run very short veg times, but in my experience this can cause plants to hermy because they have been put into flowering before they are sexually mature... The alternate node thing works but then again Ive had plants(Most MandalaStrains) that will absolutely show no alternate nodes until there well into 12/12.. I agree with elskeetro.. I like to vegg them longer and run fewer plants from seed most of the time. Nice yields from mature ladies...two cents... Good luck d:rastasmoke: