Excellent follow up work
We used to think that manual cleaning vs nutrient tuning were dueling systems, had to choose an opposite end of action spectrum
but now we know they’re synergy, the two methods. to be ordered correctly-work and decloud before nutrient tuning always makes for clean rock and it -prevents tradeoff invasions-
Your tank would be ripe for cyano invasions were it not for you robbing their whole food source before hitting cruise control. I’m linking this again to a friend who needs to be convinced of action, because we care. We don’t have to entertain an invasion or wait or lose more corals while we work to identify at the cellular level a given invader. Action steps are listed + follow up here, rare.
The small push of algae above is correct nutrient balance. You know corals won’t bleach with that minor driver in place. Some grazer feed. It’s not about total starvation -at all- nor is it about dosing fertilizer to ones tank to raise or lower N or P while all the base detritus remains, to fuel the next alternating invader. Act wholly on the reef tank if you want your investment to comply, not in parts.
*this thread is a neat non peroxide comparison. Peroxide is highly predictable in growback timing, what your rocks look like above is as good or better than ideal peroxide use

and your boil water conveys zero biological test to the nontarget area, it appears to be killing the full plant matrix based on update pics, agreed. It’s great. Agreed on coralline statements above, dosing options. It’s a seeding organism that really transfers well. Whether it lands in a tank that selects for its growth, tbd.