High CO2 level fish gasping, CO2 off since last night
I just got a call from my wife that the drop checker is yellow and the fish are gasping at the surface. She changed some water and put in an airstone. I don't understand why this would be. I have the lights and CO2 set to turn on at 1:00pm and off at 9:00pm. Both the light and CO2 have been off since last night and I have it set to 1-2 bubbles per second. I asked her to double check that the regulator is not bubbling and she says it wasn't. I had her unplug the regulator until I get home at 5:30. What could this be about.