This algae somehow magically transported itself from a different tank that I pretty much gave up on, because of this type of algae. I figure I might have a chance to fight back here, since this is a younger tank. Substrate is soil/gravel/O+, with relatively high lighting, and no co2. I can see the immediate problem, but this doesn't seem to be an algae that is overly affected by that. I've still got a healthy crop in the original tank that has minimal nutrients, low/very low lighting, and no co2.