Usually it's light/CO2 balance that's the issue if anything. First thing I'd do is reduce light by 20% and see what happens. After that I might bump the CO2 up a bit if my livestock can handle it, again just see what happens.
If it's not those two, start looking at water changes, nutrient levels, maintenance etc etc.
Honestly if you have enough good algae eaters they may solve this issue for you and give you some breathing room in terms of "imbalance".
You can remove this algae easily with a soft toothbrush. It's good to manually remove as much as you can humanly handle. Combine this with a reduction in light. This is a 'reset' to see whether reducing light is effective........... if it comes back just as bad, consider the next possibility............