If you exhaust your tents to another location, you could just add an intake fan and close all the tent vents. Then when you open your breeding tent, make sure all the fans inside are off and keep the exhaust on before you do it, and probably wait a few minutes to let the air settle a little. The negative pressure should help keep pollen that is in the air in the tent.Thank you i think if i want to do this project , i have to find another location i know what you means with pollen kind of mother nature lol