Latest growth. Green center with, dark purple outside. I have had a purple algae, growing for a long time inside my aquarium. It kind of resembles salt water coralline, and the African mbuna eat it as fast as it grows. 6 months ago.
It is a hair type alge, that grows well in my scrubber. It seams to do grow best at less than 10ppm nitrate.
The Gem lights are center in the green area. All 4 on one side. About 2 inches apert. About 3 to 5 inches away. My scrubber is angled, to to panel that hold the lights.
My nitrate is at 18ppm, after a wc 4 days ago. My tap is 12ppm.