I say that it is the light. That being said, what corals are you trying to grow? For some reason there seems to be anecdotal information that a new tank has a difficult time growing SPS even with all the "right" parameters.
I have an SPS tank and my experience started with MH and when LED became popular I tried them (AI Sol and then Sol Blue) I had three across my 180 and eventually went to 5 in order to get better coverage and try to eliminate dead spots. I eventually said "this just ain't working and went back to MH with very good results, but for heat and cost I thought I would try T5. The results were good but I couldn't get the color I wanted (not the the color of the corals but the visual appearance to my eye.
I now have 3 MH (250 Watt radiums) and 4 ATI t5's and everything is great. I like the appearance and the coral look good and are growing very nicely.
When I sold the 5 AI LED's that pretty much made the switch over a no cost transfer.