It's low-tech with no c02 injenction or fert-dosing. The bio-load is also very low, as it is currently a home to only some blue-velvet neos. The lower photo-period prevents most algea growth and keeps plant growth slow for reduced pruning requirements.
Back to the topic at hand, I would agree that considering the sunlight is important and making small adjustments should get you where you want. Thread algea is fairly irritating stuff to deal with. Maybe look into adding some anubias or java fern to your set-up. Both are traded commonly on the forum and you could likely get some through a ROAK.