Ah. Got it. I forget stuff.Cyano isn't an issue in mine, but the other tank yes. I was wondering the same thing about the timing.
Co2 build up can often lead to cyano.
So maybe the wrong track.
The blue bottle is just aminos.
No apperant organic carbon source.
Fwiw , a GREAT article on aminos
https://www.advancedaquarist.com/2014/3/corals