Ok. Reduced the lighting by 2 hours today. Can't control CO2 as I dont have a kit. I have holes cut on both sides of my lid for the filter, so I think Ill just move it from one side to the other every few days. Looks the most like staghorn algae to me, but I definitely don't have an ammonia problem. I've been changing at least 15% water every few days and the tank is mature. Hopefully the lighting will do the trick.