There's really no mystery about it - it's just what it says! 48 hours before you want to harvest, turn off all light (but keep your fans/humidifiers/vents/etc) running. When 48 hours are up, you're good to chop!
This is an exciting time for you! Have fun - your grow looks absolutely amazing!
It is crap.
48 hours of darkness just stops the plants metabolism.
A plant with stopped metabolism will not be able to prevent THC breaking down. Fact.
Do not do it.
darkness before harvest slightly increase thc but significantly reduce terpene concentration.
(baked with lab result: www.youtube.com/watch
if you doesn't have a you tube account i have a screenshot of the results in this diary:
growdiaries.com/diaries/27422-12-12-from-seed-chupa-bud
i personnally prefer having more terpene over few thc %
Hi mate, at the end of your last day shut the light off for 2-3days keep air circulating fans on an all good, best to not water a couple of day before and flush as usual if do so. Hope this helps
Good luck