We'll I think it's a great unit.Well made and all that.Since I have had it,four months,I basically keep it on the one automatic program(choice of 2)...so I haven't played around with it.I have LPS and soft coral,and from the light to the bottom of the aquarium is 36".All of the coral is thriving.I keep it at 100%.The unit comes on 7am and ramps up intensity to 100% slowly and goes through it's entire spectrum .I really like the mid day output.I can compare that to MH, IMO...After that it starts ramping down gradually,and off @ 9pm. I have this unit on top of my 220 DT along with a tek 6 bulb 54w t5ho lighting system.To compare colours between the two ,in all honesty,the T5 bulbs have nicer colour in the blue and purple range.That said,I prefer the combination of T5's with the 15000k unit.