I have a 6x54 T5 set up over my 75g. It sits about 5" off the water and about 12" or so from the first level of corals which are SPS. I am running Giesmann bulbs with 2 Actinic Blue + and three AquaBlue +. For the 6th bulb I have the option of another Actinic Blue + or a 10K bulb. Which should I use? Also, my full lighting period is 1pm to 8pm with the blues on 1 hour before and after. should this be longer or perhaps shorter?