Just to update. AF definitely took out the GHA as per the experiences shared above by many.
I continued 3-days routine up to 12 or 13 doses. I then did weekly dose a couple of times. And at times, didn't even do it for a while and then did 3-days routine for a week. I mean I was not consistent, yet I don't have GHA trouble anymore.
However, since GHA is gone, Dinoflagellates are trying to take over my gravel bed. I've had diatoms in the past. But this is my first encounter with Dinos. I'm not sure if AF works against Dinos. It doesn't seem like it can. Can someone post link to what actually worked to fight them. I'm sure a lot of people would run into issues like Cyanos, Dinos etc when we take out their competing GHA with AF.