Aquariums: Struggling with hair algae for weeks – slightly improving, but it keeps growing at the surface. Any ideas

Hey everyone,

I’ve been dealing with hair algae in my aquarium for several weeks now. I’ve already made a few adjustments:

-Turned the blue light on my Fluval 20W lamp down to 0%

• Reduced feeding

• Dosing Pro-GBL Flora Pheropohl once a week

• Water parameters are mostly fine, except Carbonate is a bit low

I feel like the algae problem has slowly gotten better over the last 1–2 weeks. However, the algae at the water surface keep getting worse, especially on this long plant that reaches the top. Right above the airstone, the hair algae grow the most.

Does anyone know why it’s so concentrated at the surface? Could it be the strong surface movement / oxygen from the airstone, or more of a light/CO₂/nutrient imbalance?

Any advice or insight would be really appreciated! 🙏