everything is smushed into the center portion of the tank atm as I make the flow correct with the addition of the jabeo wp25. so looks a bit dense but that's how I like my tanks full of color and coral. "mixed reef"....I would agree the light spread on a 40 b is better suited with the 3 footer t5's ...the reef radiance is obviously made for a 2 foot sections. but the quality of light IMO is better with the LED even with the darker edges. I have been using the darker ends to acclimate corals into the higher light zones.. its always been my plan to add at least 2 t5 blues to this setup as the blue on the LED will be maxed out way sooner than the whites. but at the same time the sterile look of florescent lighting has always leaved something to be desired by me....when under t5 kinda makes the tank feel like a cubicle at some random corperate office in somewhere in America.