I have the same fixture on my 75. My tank is a mixed reef, including some soft and LPS corals, some SPS and Clams. I'm wanting to move more towards SPS soon. I run my actinics for about an hour in the morning and then turn on the daylights. I leave all on for about 10 hours and then turn day lights off. About an hour later, I turn my actinics off. I don't have timers so this is what "Normally" happens. Not always though...lol.