This is the opinion of FastBuds and i agree with it.
The 18/6 light cycle is perhaps the most common cycle used by most growers. What makes this schedule perfect is that while it provides more than 14 hours of light necessary for the plant to perform to its fullest potential, it also offers six hours of rest.
With even 6 hours of darkness or resting period, the plant has enough time to recover and grow normally. It’s perfect for beginners that are intimidated by autoflowers. Autoflowers are programmed to grow as quickly as possible and they begin to flourish right from the get-go.
You can’t afford to stress the plant because it becomes difficult for the plant to bounce back. During a 24/0 light cycle, there’s no time for the plant to fight against stress, but an 18/6 cycle provides six hours that can be used by the plant to recuperate.
It’s also beneficial for the lights to rest a bit instead of operating continuously for hours with no breaks. The same logic applies to other appliances such as air conditioners, fans and any other electronic appliances that may be used to control the temperature inside the grow room. With a bit of a breather, the devices will last longer than expected.
Last but not least, you save money even if you reduce only 6 hours of light per day. It equates to a reduction of 180 hours of light per month! Plants in the 18/6 cycle grow extremely well, so you’re cutting down the electricity by 180 hours in a month. And now that you look at it that way, the 18/6 cycle certainly seems like a better option, eh?
So, without a doubt, the 18/6 cycle is perfect for autoflowering cannabis plants.