How critical is 100% total darkness during 12/12?

[Iguana Man]

I'm just curious to know if any and all ambient light has to be accounted for when switching to the flowering stage.

Is 100% darkness absolutely required and if some minor ambient light does occur during the 12 off of the 12/12 cycle, what effects will it have?

 

[Iguana Man]

Forgive me, I should have searched this question out before posting it. Bad Iguana Man, bad!

 

[Lester Freeman]

It's not really absolutely required as much as it is ideal, in my outdoor grows at night a neighbor has a porch light that shines from a distance, and I know damn well it's not 100% darkness especially with the moon and stars.

Even if there is a tiny little light leak inside a tent, there's no guarantee it will go hermie. But we strive for ideality

 

[Major PITA]

Absolute darkness is not required. Consistent darkness pretty much is. Plants are able to deal with cycles like that of a full moon to new moon, and back, as well as other less natural sources of light during their dark periods. I've never seen a study that shows how much light is needed to trigger problems.