flowering

if your strain says 8 weeks flower time, do you start the begining of the 8 weeks from the time you switch lights to 12 hrs or after you see flowers?

Not sure but it could take longer or less than 8 weeks, buy a scope and and just check the crystals.
my guess would be from when you switch the light's though.

I really don't go by what the seller goes by but by what the plant tells me......check those trichomes with a scope and you'll know when she is ready...

yeah you can get it down to 6 weeks even if you keep your plant stressing. I harvest my 8 week purple strain every 6 to 7 weeks. just cut one of my lights down at 6 and a half weeks and pulled 17 zips