I change over for the extra UV at the end. I've noticed more trich production after switching. The ambering seems to be temporary reaction to the light change.
What do you consider "old school" genetics? I gotta say, with the amount of people breeding nowadays, seems like every Tom, Dick and Harry are crossing and making their own strains, I don't know anymore what's good and what's not. 10 years ago it was much easier. I've been cycling the same stock for a couple years now, blueberry, vanilla kush, LSD. I'm flowering out my first run of blue dream, green crack and durban poison right now, still sitting on some chemdog, trainwreck, White widow and a few other seeds. I have a strawberry amnesia I just started, probably my "newest" strain. I'm assuming these SHOULD all amber up.
So, without ambering..WTF are we now looking for? Receding pistils, swelling calyx.. then what? Just milky? Wait for signs of trich head degradation? Magic 8 ball?