Dino Blackout Oxygen Exchange?

[Tnops]

Hey fellas, I'm fighting a dino infestation and won't a blackout where I cover the entire tank with large garbage bags heavily decrease the oxygen? The sump will be there but I don't think it is enough. Should I let the skimmer skim without the cup?

 

[GarrettT]

Will you be running UV simultaneously? Otherwise, I doubt it would accomplish much. I’d imagine it could be an issue. I personally would run it open or with a mesh screen on top. How big is the sump in comparison to the display?

 

[damsels are not mean]

You don't need to put garbage bags on the tank, unless it is heavily lit by the sun or something. Ambient light from the room is not bright enough to ruin your blackout.