Light trap, ventilation help

Have a 6.5 x 4 ft space and many ideas. Would like to ventilate both veg and flower through same carbon filter. Need light trap help to pass air from veg to flower. This is not a stealth grow just want no light leak in to flower room for night period

Easiest way would be to hang another fan in veg area and have it dumping into the flower area.

Only trouble with this is that you’ll also have excess humidity from the veg area being dumped into the flower area.

So may need controlling.

In order to reduce light levels through the ducting a couple of S bends on the ducting should be adequate or you can buy black coated ducting.

just make an "S" shape with some aluminum ducting for a light trap.

I run and S between my two tent with aluminum ducting. Just make sure theres 2 full 90 degree bends and you’ll be golden. 0 light froma 315W cmh comes through

Thanks everybody, I was really overthinking this.