You really don't need more than 4 hours a day for algae to grow. I leave lights on all day on some tanks and don't even turn on the lights and some of the tanks and there is definately a difference in the amount of algae that grows but it will grow a little bit in an unlit tank too with just daylight.
Well then, I have something wrong. I have had this tank set up with CA cichlids for the last 2 years. Water averages have been PH 7 and now it is 8 since I did the changeover with coral substrate, ammonia 0, nitrate has been on average of 15ppm.