Green algea on rocks when I have my lights on

[r212019]

When ever I turn my lights in during the day, this green like algae grows on the right side if my tank sand bed. When I turn the lights off, the green algae goes away. I kinda feel like this may be caused from my lights being old. I'm new to this so input is greatly appreciated. I could be way wrong so please help


Biocube 29
2 power heads in the tank.
2 clownfish
1 goby watchman
Live rock
Live sand
Stock lighting
No skimmer, water changes done weekly