Changing light cycle on seedlings?

I leave the light cycle the same from germination to harvest. I'm a 20/4 person but many also do well with 18/6 and even lights on continuously. I believe that plants need the dark down time so I don't think I will ever try leaving the lights on all the time. I'm also not a fan of changing the light cycle of a plant that doesn't need it. Don't forget. Auto's are driven by genetics, not the amount of light and darkness like photo's.

No, but 24/0 will definitely be bad for your plants, period. Just run your lights 18/6 from day one until harvest, this is the optimum lighting schedule for cannabis - auto flowers or photoperiod plants in vegetative growth. Cannabis can only grow so much during any 24 hour period, and this growth tops out at about 18 hours, meaning running your lights any longer than 18 hours is basically a waste of electricity. Besides, every living thing on this planet NEEDS a sleep/grow/sleep/grow/sleep cycle for proper growth. Giving your plants continuous light will just lead to unhealthy and stressed plant and stressed plants can not produce prime health. Your plants will be far healthier at 18/6, meaning growth will be better as the plant won't be stressed. Trying to grow with 24/0 is in my opinion equal to plant torture and should be banned because it is so bad for plants, especially young plants. You will not lose yield or potency or anything by doing 18/6, in fact, yield and growth will probably be better due to your plants getting a normal and healthy pattern of sleep/grow. Sleep deprivation is a well known torture technique, doing the same to your plants will just cause problems. Plants need sleep to function normally. Anyone thinking that they may get bigger or better plants by doing 24/0 is sadly a mistaken. Anyone advocating this method is clearly demonstrating a lack of knowledge about basic plant biology and a lack of understanding about how plants function. Whoever told you that doing 24/0 is ok for growing cannabis should really be banned from growing plants, it is just wrong on so many levels. Honestly, your plants will be far happier and healthier at 18/6, during its entire life, both veg and bloom. Happy and healthy pants will give you happy and healthy flowers. Hope this helps,........... Organoman.

I would think running a 24 hour light would be more stressful to plant then just starting out 18/6. Plants need sleep also.