I would go with
Skimmer Juice's recommendation. Add one or two A360's to the Tek, and you will have an amazing fixture! If you are dead set on only LED's, I would recommend three A360's for a 4' tank.
Yes... 3.
I ran two A360's over my 36 x 18 x 24 and in my opinion, it didn't give enough coverage. I don't want to debate the issue in another ridiculously long thread about what is the best lighting technology, these are simply my results.
I recently switched to T5's and the tank is doing much better.
Here is a side by side comparison of my Forest Fire Digi. The pic on the left shows the shadow on the body caused by the single source of the LED, and the photo on the right is the same spot 3 weeks after switching to T5's.
I loved the controllability of the Kessils, don't get me wrong, this isn't an 'I hate LED's rant'... and perhaps I utilized them wrong, or had the wrong spectrum. I don't know. I just didn't want my corals to suffer for my misunderstanding of the technology.
Ram3500 is running
FIVE A360's over a 56 x 24 x 26.
