Light cycle below 12H

as long as some common sense duration is used, it's more about the DLI you provide and not necessarily the hours of light, though it is directly and proportionally related. it's possible less than 12 hours could be better... it's possible it is not. ambient co2 - 35-40 DLI is a good target. you can work out what works best for your environment in vege phase or early on with an auto before you get into the nitty-gritty of flower. 1200-1300ppm co2 - 50-60 DLI .. a wider range because it depends on how tightly you control environment. As above, this is a ballpark and you must observe and react to plant for finer resolution. i've written out what DLI is too many times.. use google. figure it out. DLI, PPFD, umol/s if you can do basic math and reference a table, it should be simple to do. if you can't.. me explaining won't help anyway, lol. in the end it is abot how much energy the plantn received.. umol/s of photons in a a range of wavelengths.. if you apply photons at a faster rate, you achieve teh max DLI with fewer hours. it will not matter much whether you get max dli over 12 hours or 18 hours. it's the same amount of energy per 24 hours relative to your atmospheric co2 and your temp/RH.