Is complete darkness required during dark hours on veg. stage

[MaxiBelas]

Hi,

Just started few new ladies (hopefully) in my grow tent. My light schedule is 18/6. How important it is to have the 6 hour dark period "completely dark" ?

I ask this because currently I have a carbon filter + inline exhaust fan with some ducting doing the exhaust part. I got these to combat the lovely smell in flowering. At this point, this setup is bit overkill and I would like to move to just a one 120mm PC- fan blowing warm air out. This keeps the climate just fine at this point.

But, the issue I'm facing is that with the PC fan setup, the ventilation hole in the roof where the fan sits, would be open and some light would get in to the tent from the room itself. As with the inline exhaust fan, there is ducting which prevents light getting in. Can't really introduce ducting to the PC fan setup so..

Thanks

 

[f-e]

Can you make a free flowing light trap? In it's simplest form, a card box sat on top of the tent, over the fan, with a good sized hole in the back, facing the wall. Any light getting in, has first bounced off the wall. You can then get a second larger box over the first. It has a hole in the front. So light must get in the front of the second box, get around the back of the first box, to get in and through the fan. That 3 or 4 times the light must bounce. If the surfaces are black, the tent will be black.

24 hour light will veg just fine, so a constant level of night time illumination wouldn't bother me too much. Though if they are awake, they will try and grow, and won't get any real calcium uptake without some good transpiration levels. Thin stretchy light green growth would soon show.

 

[HempKat]

The only time complete darkness is required is during the flowering phase. During the veg phase it's not really an issue. Some even run their lights 24/7 during veg hoping to get some extra growth, although personally I don't recommend this. Plants are living things and all living things benefit from having a rest period. Plants don't sleep like people or animals do but the dark period is essential the same as sleep for a plant.

As for the light issue you describe an easy way around that is on the outside where the PC fan will vent build hat is called a light baffle which is basically a structure that makes the path of the air being vented out take 2 90 degree turns before it reaches air. You can build one out of a simple cardboard box if you anted to. The important thing to remember to do is to paint the inside of the box black so that no light gets reflected into the grow space. See light only travels in a straight line from the source there is no way for it to bend around a corner other then by reflecting off a light colored surface. If you make the surfaces inside the baffle black then it wont reflect between where you tent vents and the source of the light. If you do a search here within this site for light baffle you'll probably get more detailed info on how to build one maybe even complete with pictures. I've inserted a couple of pics of my own that illustrate the concept but they're very basic and don't really match your scenario.

Here's something else for you to consider. The setup using the inline fan and carbon scrubber may be overkill right now when you are in veg but I can pretty much guarantee it won't be when you reach flowering. Depending on the size of the fan and scrubber it may not even be enough. It's best to just get used to running an inline fan with a scrubber all the time rather then having to switch things once the smell gets too strong.

 

[Three Berries]

Anything less than full moon light is OK I would think.

 

[Creeperpark]

I always try to make it as dark as I can on all grow's. You can only do so much with what you got and you'll just have to make the best of it. Yes, total darkness is the best choice.

 

[StickyBandit]

Anything less than full moon light is OK I would think.

Yeah, I always wondered about the moon
I also read on an STS tutorial that good genetics shouldn't hermie under any circumstances, if that's what you're worried about