Here's the deal.
There a couple threads about million pages long on this.
The the current consensus (and actually always has been) is nutrient limitation can lead to the proliferation of certain organisms. They can then establish an Dominnce in the tank by leveraging conditions in the biosphere to tap resources that then out compete other more Benicial microfloura and fauna.
So without a microscope and a phd , what you can do is to increase nutrients and introduce other more beneficial and diverse organisms in to the sphere to-out compete the nusance organism. This is usually combined with manual removal or killing of the organism.
This is the basis of most dino treatments in fact. Although it may currently not be recognized as such.
Yes, it's a tiny bit counter intuitive , I have alge So feed more. And yes you may experience a slight bloom , but the introduction of a competitor is a very important step imo to combat this.
For years with typical cyanos , I've said remove as much as you can , do water changes , and add bottled bacterias. Current is reccomend DT tims one and only as it has several strains. The next step up from there and is Micofauna treatments , aged live rock, garf grunge , Fiji mud. The mud is the least expensive of those. GArf grunge is
the coolest cuz you can order corals from Sally Joe while you are at it.
Jus sayin , a GArf bonsai from GArf.