The cause of this algae outbreak is importation and nothing else. Its random mix of what we bring into tanks, and it makes sense that changing one or more variables (like on the micronutrients post) alters a burgeoning community either pro or con and they either do better or worse, in that case worse.
No amount of quarantining or plant inspection visually would prevent any outbreak, as even fish slime coats are vectors for algae and certain invaders. you guys would be amazed to see some high res expensive carmera macro shots on reefcentral chem forum of this guy who has shown that invasive dinoflagellates are spread tank to tank by fish as well as by substrate. His pics literally show the oodinium-verified dinos stuck to the slime coat like teenage pimples. same principle for control of import in fw planted tanks...sure you can visually id and dip for snails and some invaders, some obvious algae, but in the end its a random mix and your direct action on the algae usually decides the fate of your tank.
Sure people get lucky with X grazer that controlled it naturally, or some change in tank stasis, but in the end that which is repeatable comes from direct not indirect action on the algae. I predict there is no form of tankwide nutrient modification that could control this, and you may have to repeat as needed until you win against the colonies wherever they remain to potentiate again after each treatment. eventually you will win.
I do not believe you can ever eliminate the source of this algae, so dont bother. just be deliberate if this is what you are given as a test. You can beat this algae out of your tank, but to prevent it from coming back in, we dont control that only blind luck does. bba is my nemesis in my 12 yr old tank, not spiro. to each his own battle lol.