May Meeting

[ingg]

There is, Kris, but they cannot process it due to the acid levels in the water.

If we pump smoke in to a room and close you in it, you will choke. Kind of sort of the same idea - there may still be oxygen in the room, but you still choke on the smoke.

Still oxygen in the water, but the gills are being "choked" by the carbonic acid in the water column. The surface gasp is instinctive - get to where gas exchange happens.

[SCMurphy]

Actually you can deplete the O2. Fish, plants, and bacteria are all competing for the 8 to 10 milligrams per liter of O2 that you might start with when the lights go out. If you are conserving CO2 and have no surface agitation, the O2 levels will drop steadily and you start getting gasping at 3 to 4 milligrams per liter of O2.

[ingg]

Agreed - at night. That said, I've never observed anything like it myself, but I guess if you stock fish heavily enough?

I'm referring to daytime gasping (the first scenario I'd laid out) in my previous post.