Do you have a microscope or at least a jewelers loup to determine color of trichomes? That's really the only way to determine readiness with any high level of certianty...flushing is a bit controversial...personally, I do lower my ppms to about 50-100 for at least 4-7 days before harvest in hydroponics, but I've never tested out not flushing at all. If you do decide to flush, timing will be no different than a normal photoperiod strain...in soil I think flush is 7-14 days? Not 100% sure on that, haven't done soil in years.