Ok so Im not sure if it's the earlier sunrise but I was getting some green spot algae (very minor) on the side glass facing the window. Tank is about 3 meters from the window but now gets diffused sunrise light from sunrise to about 9 am when the tank lights go on. After that the sun goes behind a building. The GSA is on the glass below the substrate. I've now decided to change to the time the lights are on. There were on from 9am till about 3 pm. But Ive changed that to 2pm till 8pm. For one I'm not at home during the day and it's nice to see the lights on when I get home and for the early part of the evening. Does this not interfere with the natural light cycle of fish? Would love to know what other APSA members lights on times are?