How dark must it be?

I have my plants in 12/12 in a closet. How sealed does the closet have to be for flowering to be successful? Is it ok for some light to leak in, through the vent low down and through cracks in the door etc? There isn't much getting in, just a tiny bit.

you should be fine with the cracks
in the door but if its possible cover
that vent with something.

I'll probably put a shoe box or something over the vent. That way air can still get through but the light won't. Thanks!

You shouldn't be able to see your hand if you hold if it up in front of you. Just a rule of thumb.

If I close my eyes I can't see my hand! Only messing, I guess I'll have to do some extensive light sealing work then. Is it really that critical? I mean in nature what about a full moon or something?

In nature the full moon doens't shine every night. Yes it is that critical. Really.

Ok Mogie, thanks. I'll seal up those cracks asap. I should have some pics posted tomorrow too, had a camera today but the battery went dead.

a 1000 watt HID HPS/MH is not quite the same intensity as a yellow class star like our sun. The sun is a powerhouse of light and energy - so a measly little full moon isnt going to bother plants, or car headlights, or a streetlight.

in your closet, the little pin hole of light is like 100 full moons compared to the strength of your HID compared to the sun. Hope that makes since... 100% darkness for the win.

Dark as dark can be otherwise hermies will molest your grow room and next thing you know your a seed bank

whats wrong with being a seedbank?