Mags put out a ton more water at higher pressures vs. a MJ1200. You could, be good for a nano system, but it won't buy you much water flow in anything bigger.
55g reef, 2x250W 10k MH
+ 2x96W PC
actninc, 10g sump, AquaC Urchin skimmer, 65lbs LR
xenia, mushrooms, wels. open brain, fungia radiata (orange), green eyed zoos
flame angel, mated pair of false perc, 6-line, firefish
20gH electric yellow cichlid