Looking for some input/help; my tank is suffering a big GHA & Cyano issue

[Ryanerickson]

I had a algae outbreak at the beginning of summer gha and others all at once it took about 1.5 kg of rowa and a 3 day black out. Jason 3-4 weeks of rowa will not get rid of it I actually found it got a bit worse at first. I have been changing out 300grams plus every 2 weeks of rowa. Finally 3 months later it's 98% gone.