hey man, those white hairs are what we call pistils, when you go for the chop they will all turn brown anyway. So when to harvest ? if you dont want to go off the trychomes you're not gonna be able to be real precise, and tbh you can't tell from the pistils (every strain is different, and they all turn brown) if you dont want to invest 10 bucks on a 40x + magnifier then the best advice i can give you is go with the reccomended growing time from the breeder and add 2 weeks to that - usually breeders under report the amount of time you need for a harvest... Otherwise trychomes are really your best bet. Closer to the time you want to time the chop based on your drying room's humidity : <40% chop the day after your last watering; 40-60% chop two-3 days after the last watering; 60+ three to four days after. Then take the plant whole, hang it upside down to dry. This allows the bad + harsh tasting photosynthesis chemicals to distribute from the bud towards the stalks, stems and leaves that you remove, giving you a smooth tasting smoke. Hope this answers your question bro ! 🚀