1200LPH pump , water pump your saying? or air pump?I would put a 1200LPH pump on that box.
20LPM should do well for that box for a few plants.
you can do it either way: airpump/airstones or waterpump/waterfall. both have their good and bad points.1200LPH pump , water pump your saying? or air pump?
Sorry I'm very new to Hydro
and less heat.small waterfall instead. more DO.