Light Leak

So I just switched my lighting to 12/12. I want to avoid any light leaks so I closed off the screens on 4x4 tent however tent is showing negative pressure and I wonder if enough “air flow” will happen.
What am I missing? Do I have to open a screen when lights come on every day?
What do u guys do?

Just leave the ones at the wall open but only enough so that creates a light jet of air through the tent keeping good negative pressure. None of my tents are a 100% light proof ever but its small and so dim that when i.look in it looks dark.

Some make baffles some open and close, you can close the flaps but open a zip 30cm to let air through in a dark place as this makes less light leak.

Its a pita but ideally we would grow in dark or exsclusive rooms not our bedrooms and such

If you don't have good ventilation when the lights are off, humidity will spike and cause powdery mildew or bud rot. Use a light trap out of cardboard to block light

I left the one on the wall open but was worried some light may reflect down through it.

My seed testing tent is in my veg room, plenty of light in there. The vents are open and it hasn't caused any issues.

I have this exact battle. Because my tent is in my room I watch tv at night and the light from the tv is rather bright. I have a piece of cardboard that I block the bottom screen with so no light can get through, but let’s be honest these Chinese tents have light leaks everywhere. I have since stopped watching tv when I go to bed I just stay on the couch longer. I now also leave the door to my room closed so no light from the other rooms of the house can get in.

Here is a simple light trap someone made.

I woulda put it outside the tent but it doesn't take much to stop the light

The little stitching around the zipper allows light out - mainly cause the ceramic halide is so bright. I doubt if outside light is intense enough to cause an issue shining in.

Wow that’s a great idea! I think I’m gonna do that. Ya outside makes more sense to me.
Thanks for sharing!

My test is to stick my head in, zip my head light leak tight with zips and wait thirty seconds for eyes to adjust. So long as its dark and leaks small and dim im happy