sup brick!?
to be honest the difference is marginal id say ive tried it both ways, little difference when your weed is high end to begin with. the best little tip ive found for swelling the crystal is to run a dehumidifier in the last week of flower/flush likewie it will help with the drying time.
The problems I have with people saying an extended period of darkness doesn't work or doesn't make much difference based on their own experience is with over 2,300 known strains out there and unknown numbers of mystery strains I doubt if anyone has grown enough strains and tried it enough times in the best of growing conditions always maintained at the very same level to really be able to say an extended period of darkness does not work or does not make enough difference to be worth it.
It is possible that what few strains they have grown and tried it on did not respond much to an extended period of darkness so they declare what scientific testing to work nothing more than a myth. Sometimes the people who say it is a myth do not do side by side comparisons where both crops are grown in the exact same conditions and given the exact same care and the plants may have been grown from seed rather than from clones and the seeds may have come from other bean runs and in some cases even different knockoff strains that were not really close genetically were grown so there is a total lack of control in what they consider to be 'accurate testing.' Others listen to them and think ' well, they tried it and it did not work so I won't waste my time. The person who thinks that after reading where someone else said it did not work for them and then does not give their plants an extended period of time finishing them in total darkness might be growing one of the strains where a big difference might occur and they might lose out on a 20% or 25% or 30% increase, all because someone else said it didn't seem to work or did not seem to do much at all.
I knew people back in the 70's who had already figured out, by accident and not through scientific testing, that harvesting their plants before sunrise resulted in higher potency smoke. Since then it was discovered that THC works as 'sunscreen' in trichomes heads. It protects the delicate inner glands from damaging sun rays. In doing so some THC is lost each day, it breaks down as it protects the inner glands. Each night what was lost is replenished and a small additional amount is produced so there is a slow gradual increase, so because of how light does break down THC when someone harvests before daylight, or if they unplug their lights or turn off their timers after their final light cycle before harvest their plants do not receive any light before they are harvested so there is no loss of THC that would not be replaced due to there not being another period of darkness to replace it in.
Since that is a known fact, or at least known to anyone who knows the inner workings of trichome heads and what the plants reason(s) are for producing THC in the first place are, it would only make sense that an extended period of darkness before harvesting would result in higher potency pot. Yes the percentage of increase will vary from strain to strain but since people will pay, and in some cases overpay, for other things that in some cases are only claimed to work and in some cases known to work but again only to a varying degree, to increase potency, things like using high dollar soils and additives and nutrients and various supplements and different types of grow light bulbs and UVB bulbs etc., why in the wide, wide world of sports would anyone ever pass on doing something that has been scientifically proven to work to some degree or another that will not cost them a single penny to do? Doing so would be illogical.
Something else I really never understand is how anyone could believe growing in their basement or in a closet or in a growbox or in a grow tent or in a greenhouse gives them a controlled enough environment to be able to accurately compare their perceived results to that of cannabis grown in closely monitored well maintained conditions that is then scientifically tested in high tech labs. It just does not make any sense to me that anyone can actually believe that their perception of and belief in some growing technique is more accurate than the results of actual scientific tests.
Another is, of the people I have seen or heard say they did not believe it worked or did not make much difference is all so far have only talked of potency as in how high or stoned they felt, but none so far have said they thought to pay any attention to the duration of high or stone. Someone might grow strains where the high or stone does not seem more powerful to them but their high or stone might still be longer lasting.
Keeping humidity in the proper range is more important than many people know it is. There are some very potent equatorial strains that grow in high humidity areas but when you look at 'numbers' most high-test landrace strains have evolved in drier areas, like Afghanistan. The aridity of the areas of Afghanistan where Indica strains have evolved is more than just apparent by the trait of large dense flower clusters thickly covered in large trichomes. This would only be an advantage in an area of low humidity, as flowers will mold in anything more. Hence the airy sativa flowers due to their evolving mainly in areas of higher humidity and the dense flowers of indicas that evolved in areas with much lower humidity.
There are many examples of non-cannabis plants producing resins in order to protect themselves from drying out. The waxy coating on cacti and other succulent plants is a prime example. Marijuana flowered in humid conditions will often have a longer stalk on the glandular trichome than the same strain grown in drier conditions. That will give the appearance of being very crystallized but it will likely contain less THC than
the same plant grown in a drier environment. Shorter trichome stalks are preferable because the gland heads of longer trichome stalks are more likely to break off during handling.
So yes, humidity is important but it is not only in the last week of flowering. For some reason people seem to think that things like proper humidity are only important during the final stage of growth and that is only when they will do their 'magic' when it actually is important throughout the entire life of plants. Someone will try something like increasing humidity in the final week of flowering and they very well might see positive changes, but their error is to assume that means they increased humidity at the very best time, when they would receive the most from doing so. But they fail to pause to consider the greater gains they would have had if they had maintained the proper humidity range all throughout their grow. They do not realize that the positive differences would have been greater than what they achieved by only increasing their humidity for the final week of flower.