Apologies, as this must have been asked many times before but a quick search on here resulted in nothing.
As the title says, what is the best lights on/off cycle for autos (24/0, 20/4 or 18/6 etc), or does it change dependent on what stage of growth the plant is on (germinating/veg/flower)? Currently I have some 1 week old seedlings on 20/4 (lights on/off), as I'm guessing the 4 hour dark period will help with the root development and the 20 hours light will help leaf development.