6/18 flowering cycle

Why risk an entire grow on some sort of out there weird experiment??

I'm guessing you are using ON/OFF for your photoperiod remarks. So your first was a photoperiod of 13 hours, and you are looking at trying a 6 hour photoperiod. As you can see below, 0101 is grasping at straws with, "the intensity required to get to ~35-40 DLI over 6 hours might damage the plant." This is true but vacuously so... The light intensity with respect to the continuum of pressure gradients in the medium and air, bound and unbound active water, temperature in the air, leaf temp, and a few dozen other mandatory variables would come into that equation. That is the "might" he had to use to qualify... I do this type of photoperiod all the time. Real scientists, like Dr. Bugbee (runs an entire university's hemp research program, one of the first hemp program designers, has decades of field scale hemp research and is an excellent science communicator) have opined on this topic. We don't need to wave our hands and defer to 'generational knowledge' nobody can seem to actually put into words. This is science, not an esoteric cult ritual. One caveat I would not before explaining is this: your 13 hour photoperiod, if it was with photoperiod cannabis, likely only worked due to either (i) smart red photon application or (ii) the cultivar happened to be genetically predisposed, like having relatives at the equator or poles. Generally speaking, the 12 hour mark is safe for almost all modern hybrids for a photoperiod which leaves enough remaining time in the day to achieve critical levels of phytosensitive hormones in the plant. So you can decrease photoperiod always with results, but going above 12 hour photoperiod without having an auto is a crapshoot and luck based unless like noted above. Shortening your photoperiod means two things. Your plants are (1) losing daytime and (2) increasing dark period. 1 = you need to make up for lost DLI, either by canopy to fixture distance or intensity of fixture...; do this right and you will experience zero negative impact of shortening your photoperiod 2 = your plants now are not only anticipating the season rapidly ending but are also being given huge swathes of extra time to breath deeply/repair trichomes/and so forth. You are essentially maximizing her time at the spa Do these things right and you, also, can be a 56 day king. Folks say "this is a 11 week sativa blah blah" but then you apply a trivial amount of botany theory and boom, pulling her at 56 nights light the rest. 👽👽👽

6 hours on? Why? the intensity required to get to ~35-40 DLI over 6 hours might damage the plant. DLI is DLI. whether you give it over 18h or 12h. It makes virtually no difference and this is suppoted by empirical evidence, not anecdotal pipedreams. The exact DLI your plant can handle is determined by temp, rh, and ambient atmospheric co2. These aren't 'my thoughts' nor just experience. It is existing, generational knowledge. it is better than a person's thoughts based on small samples and wildy fluctuating variables.