Two room grow room Help!

I was wondering how would i supply my two 5 by 5 veg/flower rooms with some fresh air while there are different light timings... How do I vent through the two rooms without having the other receive light when the other is off?

i use speaker cover fabric...no light what so ever and good ventilation. You can buy it on line by the feet or roll. good luck

There are a few things you can do...usually some tubing or cardboard work will be fine. If you do tubes just wrap the tubes in a U through the connection wall sooo (|) and if you do cardboard, paint the inside black to reduce light as much as possible. While you do have to be strict about NO LIGHT, as long as any beams are light are not landing on the leaves you will be OK. If you dont get enough airflow, add a small fan to the separating wall.

with a light trap...