What does the bubbles formed by Cynobacteria consist of?

[Roggio]

Are these nitrogen? After the hurricane I have re-introduce vodka dosing to my tank with a lot of success in short order. My refugium is covered with a thick mat of cyno daily. It's only growing under the horticulture lights. I'm currently using the Kessil H360. Prior to vodka dosing I had no visible cyno growth. I'm up to 30ml a day on 500g total water volume. Now that my nitrates are under control I plan on dialing back.

 

[cilyjr]

I'm guessing oxygen as a byproduct of the photosynthesis.

 

[Randy Holmes-Farley Verified Community Expert]

Bubbles that form during the day are O2. other gases formed probably dissolve away before making bubbles.

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, Cyanobacteria are one of the very few organisms that can consume N2 in reef tanks.

 

[beaslbob]

+1 for O2