Robertsanswered grow question 2 years ago This is a very controversial issue and you're going to get a lot of different answers. If organic you don't need to flush. Now if using bottle nutes in soil 2 weeks. Hydro at least 1. I begin flush once bulking finishes. Mass majority of white pistils have turned brown. Trichromes getting cloudy. Cloudy Trichromes with a few amber on buds themselves, not leaves is ideal.