Hey there, great question ! There are several methods that folks use to guesstimate when they should harvest but basically none of them work because different genetics have different traits and different phenotype have different traits even within a strain. so some folks say wait until you have 30/40 red pistils, but you cant really tell this way. My point being some genetics will have loads of red hairs and still not be ready, others will mature in stages, etc... The other technique people use is simple timing, the breeder said 10 weeks so i chop after ten weeks, but usually you want to slap on a few more weeks on that in my experience. What you're left with is looking at the trychomes, only looking at the trychomes can you find if the plant is actually ready and start timing it. So you need something 40X magnification (i bought a pocket microscope on amazon for $1.79 lol) to 60X and just look at the trichomes to see if they're ready, i'm looking for all cloudy few ambers, but most folks look for a "balanced high" with around 20% amber trychomes... it's all a matter of taste, but in my opinion it's better to have full control and a good understanding so the choice is yours to make. Hope this helps growmie ! ๐