In your case its only a 4 hour difference, but if you were vegging at 20/4 there would prob be a bit more noticeable differences imoI have some in a veg room and some in a flower room and don't see much of a difference, the ones under 1,000w HPS are taller then the ones under 1,000w MH.
I veg 16/8 to save on running a 1,000w 24/0.
They are blue mystic from the nirvana shop, I'm only asking this cuz I have a random bag seed I just flipped over to 12/12 last night and was wondering if I could grow a auto with the same light schedule so I already have another plant growin incase my random seed is a male, this is my first grow with the random bag seed it's 42 days old and I just switch it to flower last night.some auto do best under 12/12 others 18 others 24. what does the breeder suggest ? if your not sure tell us what they are . 12/12 will work better in most cases people use co2 and hps . and there veg room is only cfl . huge difference there. only way to know is have 2 rooms and next time you know what way to go next time.
No ya that's what I was worrying about too, I'll experiment and see what happens I have 5 AF seeds so why not use one and start it in a party cup haha, and see how big it'll get under 12/12 till I find out what my current plant is.If you just want to grow out the auto in the same room as a flowering photo, it will peer just fine, but it might not get as big as it could. But if it's just to get in another plant in the same space, it's fine I guess.