Ithurtz-
Ok i understand now how the trough works and you will have your plants on the trough and the trough will sit at a slightly higher elevation that the top of the large tank so that the water gravity flow into it.
question- why do you need this little tank? is it going to be continuous flow or intermittent? Are you pumping from the big tank to the little tank then again from the little tanks to the trough?
Newbie ask alot of questions lol