Would this work ?

I have some seedlings getting ready to go in the tent and have one ready for harvest .
Will this be good to dry her out ? I have a 4" hole top opposite side the 4" hole on the bottom connected to the tent drawing air in . I will close the top of the box up for darkness. It is only one plant so no need for a big box .

.

Ingenious!

It may dry the plant out too quick, there's a lot of air going into your tent.

.

I can damper the air being sucked out .

Another great instance of Stoner Ingenuity

If you find there is too much air being sucked through the box as Hobbes mentioned, you could put a towel or other material over the intake hole to slow down the rate of airflow. Just make sure you've got other passive intake going into the tent.