how much light is enough to stop flowering?

i have a seperate closet that i move any plant in flowering to for the dark 12 hours. i was just wondering how much light can stop a plant from flowering? is the lit end of an extention cord (the end lights up when plugged in) enough light to stop the flowering process?

from what i understand, small "glows" are ok.
If it's that much of a concern, put some electrical tape around it to cover the light.

ohhhh der why didnt i think of that. theres also a small crack at the bottom of the door but when i go in and shut the door i cant see my hand in front of my face

it's been in my experience that the easiest solutions to the problem or sometimes the most difficult to derive.

"less than 1 footcandle" that's the way I've read it... As always, green light has far less effect.