If the light has seperate ballasts for the 03
and day's, your best result will come from just using the actinic lighting for now. Most nuisance algaes will not do well in that particular spectrum. The coralline however should do fine.
Try cutting down to 6-8 hrs a day for a week and see if that helps. If not, reduce it another ˝hr a week until you do see some better results. Keep in mind though that this being a newer tank, the fuel source is still in the tank and needs to be burned up. Once the diatoms die off they will release silicates into the water anew. I would suggest toughing it out for a little while before you start altering things too drastically.