I had this blue green algea so bad I almost gave up on the tank. I was ready to just sell the whole tank I was so mad at it.
I was so fed up with it I took everything out of the tank. I had sand substrate I removed it all added a plant substrate. Re planted the tank but there were still bits of BG algea left in the tank. I raised the light up 4" From the water surface.
Cleaning the filter was and is key to getting rid of this stuff. It thrives in a dirty tank that has low o2 with high light.
I now keep the filter clean and my water flow is nice and strong. Allowing for good flow around the tank. I also have more surface agitation and added more plants. Since doing this I have never seen a spot of BGA. Or any other algea yet I added rams horn snails to the tank and they keep it spot less.
How often do you clean your filter?
80gal planted Angelfish community, 100gal SA cichlid delhezi, 7 gal betta.