I just started a 150g build and will be running to reeflo dart one will be closed loop flowing through four 1" seaswirls and the other will be a return that will be the supply for my aqua c EV 240, two BRS reactors and my biopellet reactor. So i will be following along. My is 72x27x18 so I will need some flow. Lol
Still building the stand but to give you a idea it will have five holes. Two 3" for overflow, two 1" for return, and one 2" for the intake of the closed loop mid way down. Water will be sucked in and pushed about 2 1/2 feet up then split four ways to the seaswirls in each corner. Each one will be pushing about 900 gph. I hope this helps and sorry I have not got it setup yet.
Mags can over heat if ran external because they can't get rid of the heat like they do in water. They don't most of the time but can. I would try to find away to use the dart.