light cycle question, help plz!!

i found this plant outside in my backyard and its been growing for a long time.
i dug it up n put it in a big pot and in my closet with a 20w florecent tube lite.
ive been using 12 hours of light and 12 hours of dark.
am i using the right light cycle? and what other light cycle i use for flowering?

12-12 is flower, anything more is veg. how long has it been on 12-12?

for about 2 weeks. i havent turned the light bac on cause i wanna put it in 18/6. is that goin to do anything. ill get some pics up once i find out how to use this camera.