Requesting Help With Strategy, Cyanobacteria/Tank Stocking

[demicent]

Happy New Year!
I am in the process of cycling 12 new tanks.  Several of them are cycled.  Most have only pest bladder snails or a few Nerites.  No fish.   

Four of them have cyanobacteria, which I merrily spread through the tanks by moving an infected square of Java Moss to see how it looked.  I have been spot treating with Hydrogen Peroxide and manually removing the small patches, which I can smell even with the lid closed.  Burns my nose. Affects my breathing which isn't good to start with.  Now here is where it gets confusing for me.

I am stocked up on Maracyn and want to treat the tanks.  I am gearing up to slowly stock the tanks, which range in size from 20 gallons to 5.5 gallons.  Since there are no other occupants of these new tanks, can I move the first batch of fish directly into their permanent homes, rather than the dedicated quarantine tanks?  Can I wait to treat the tanks for Cyanobacteria with Maracyn until after the first fish are in place, since I would be treating the fish with quarantine trio anyways? Then I wouldn't have to do it twice. 

Any help with a strategy appreciated.

Edited January 1, 2021 by demicent

[Ken]

I would get rid of the cyanobacteria first. Killing it may give your newly cycling tanks trouble, and it may take more than one treatment. I wouldn't want to be dealing with that and the hiccups you're likely to encounter when you start adding fish. 

After that the first fish in a tank are in quarantine. There isn't anyone else to pass stuff to. No need to move them around. Follow the med trio instructions and you're good to go.