noob lighting question

This is more of a question to be prepared in the hopefully near future. I was wondering when i need to switch(or how to tell when to switch) to a 12/12cycle. Right now im doing a 24/0 cycle under a 27wcfl for my lone plant(5500k). Its a little under 6inches and its in its 3rdwk of veg (day 18 ) I know i still have plenty of time but just wondering so i can be prepared, i typed in a couple of searches but couldnt find exactly what i wanted. so pleaaaaase help.

p.s.
while im here how often should i mist my leaves with water?

It depends on what you want in terms of size and yield and how big your growspace is

you can flip them to 12/12 anytime (even from seed)

but if you want them to be mature you look for branches that are uneven or the begining of pre-flowers

keep in mind that they will grow 2 to 3 times in size once you flip em

PS no need to mist em, not saying you can't but be careful because drops on leaves can cause burns

First, you need more light when you go to 12/12, and it needs to be mainly 2700k. Decide which 12 hrs you want to be dark. Say, lights off at 7pm and on at 7am. Pick a day, change your res and go to bloom nutes. Do that at say, 6pm then turn lights out and you are in flowering mode.