help plz

Ok I have a serious question that I need answered asap. I have a 3' T5 coralife dual HO light from my 45 gallon reef tank that I had to break down due to a major problem. Anyways the light is only about 72 hrs old and was wondering would this make a better light for the cabinet instead of my 400 watt metal halide. I was thinking maybe mounting it vertically on the rear wall. Any ideas would help. I have been trying to find an answer all day and havent been able to find an answer. Please help!!!!!

Keep the 400MH. The only thing is you have a lot more heat with the 400, if you have good ventilation then throw both lights in there and give it a mixed spectrum.

I got plenty ventilation its just a matter of if it would be better than I wanna eliminate the mh