You should harvest when the majority of trichomes are milky white. If you don't have a magnifying device, can just eyeball it when the pistils are all brown, and 70-90% of them have shrunk and curled inwards, giving your bud and calyxes more definition. Pay attention to the calyxes on top, wait for them to swell up and become bubbly and round. At least one more week in my opinion. I usually go the extra week on top of what breeder recommends for more weight.