Closet space - lighting leaks and smell questions

Hi all.

Our babies are in a massively long closet - 2' wide but about 15' long! They are only 3ish weeks out of their seed cases, so they are still small, and we so far plan on keeping them on the one side of the closet only. (two sets of double accordian doors with 3 feet between them, 6' on each side and nothing in the middle)

Because of the type of doors, there is a LOT of light escaping around the top and bottom, and some in the middle. I don't care too much about that. I am concerned, though, for when we put them on 12/12 schedule that the light coming from our room may hurt their dark cycle and lead to hermy plants. We're putting up a drywall piece between the two halves of the closet from where we use to where the plants are, so there won't be an issue there. Just one around the doors on the one half.

I'm considering using a black-out curtain like you'd use around your windows to block out heat/light. Get one big enough and mount it properly so it covers the entire doorway, so the door cracks aren't an issues. But I don't know how well that would work, or if there is a better option.

What options would any of you suggest to block the lights? Others seeing isn't much of an issue. The only ones that *might* find the lights on would be my 1 year old and my 7 year old. We hope to have the curtain up before the older one notices if/when they go into our room... But that's it.

As for the smell, I was thinking about making a carbon filter, and have that be vented out of the closet through the drywall temporary wall placed in between the halves of the closet. Then just need a good fan and some duct tubing and we'd be set to go! (I think, that is) The air intake I think would be kept passive under the bottom of the closet door.

Would the minimal light coming from under the door during the plants' dark period be an issue as long as it's not too bright? The room's lights are on the ceiling about 10-12' above the closet but some light DOES reach the bottom. I'd doubt much goes under, which leaving that much WOULD help the air intake of the closet for sure. I just don't want to herm out the plants by having lights go on or off throughout their "dark" cycle when/if needed as it is a working room of the house.

Oh, and I'm REALLY starting to be concerned about how much my house is gonna smell with these guys! They are only 3 weeks old, but my whole room smells like cannabis when you walk in there! The closet is closed and everything, but still!!!!!

light leaks like you mention, under the door, are NFG. You must prevent this. There can be a light baffle where air can enter but light is 'trapped'. Though under the door is a challenging place for this. Maybe a dark fabric skirt fastened to the bottom of the door?
Smell in the working part of your house will be an issue at some point. If one can't exhaust the air outdoors to a safe location then exhaust fan and charcoal filtering is used.