Robertsanswered grow question 4 years ago This is a personal preference and depends on the bud effect. If looking for peak thc levels. I use a few dollar jewelers eye 60x . I look at trichrome heads. When mass majority in plant is milky cloudy then start flush and let plant fade 2 weeks roughly. Happy growing and hope that helps. Enjoy the harvest 🌲🌲🌲👊