I'm running the lights 8 hours a day? Think it's no much? I've never had really any problem with algae before. I got a black background up, replaced the goldfish with some Zebra Danios. These guys are fun to watch, its like follow the leader in and around the rocks.
I have no idea what they were attacking, but it was a frenzy.
Follow the leader round the rock. (They were doing circles.)
I finally had one stay still long enough to get a shot of his colors and was photo bombed. These guys have really striking colors.