Like jon said, the best t5 imo is the 6x60" retro. Ran one for yrs on my 125g, could keep anything anywhere. But moved on to a 3x250w mh retro. It is MUCH better for a 125g. Think about this. Once a year i replace my bulb's so MH is 180bux, for 6-60" t5's 150bux but for 14 t5's....heck no 322 bux. The 60" t5's are going to penetrate better as well. But imo your much better with the mh's.