Single Fish Gasping At the Surface

[Volcano]

There is one fish (out of four white cloud minnows) that seems to be lacking oxygen for some reason. I recently installed a CO2 pump, could this be affecting the fish? Do I need an air pump to balance this, and why is it one particular fish? Apologies, my camera is a dinosaur. Any advice would be helpful, thank you.

Edited March 12, 2021 by Volcano

[Colu]

I would add an air stone it could be low level of desolved oxygen 

Edited March 21, 2021 by Colu

[Volcano]

1 minute ago, Colu said:

I would add an air stone it could low level of desolved oxygen 

Thank you, I will do that!

[WhitecloudDynasty]

Since you added the co2 less DO is in the water. Adding an air stone will defeat the purpose of the co2 pump, since ill dissolved the co2 fast while adding in oxygen. The fish just need to adjust.