You gotta get your tank balanced. Try to get your co2 levels up to about 25ppm.
Are you fertilizing at all? Maybe you need to.
If you haven't already done so, check your tanks nitrates and phosphate levels.
An imbalance of one nutrient over the other will limit your plants ability to compete and algae will capitalize on that. Different algaes will prosper under different conditions.
Check out the post at the top of the General section titled "all about fertilizer". That should give you a little insight as to what might be going on in your tank.
It could be a shortage of macros or micros. The only way to find out is to test.
FILSTAR Pimp #2
75 gal heavily planted,50/50 Black beauty,Eco-complete substrate, Pressurised CO2 with solenoid, ph controller, AB Reactor 1000, 330 watts 9325K GE PC lighting,Ehiem Liquidoser, 2-Filstar xp3 canisters.