I run my areators on the timer with the livewells open while fishing.....I will close them when running to a different spot with the recircs on....when I stop to fish again I open the wells and turn on the aerators on again....with the drains open it lets the bad gases out along with what the fish puke up.....With the VT-2 vents it's letting the hot air along with gases out.....even while fishing...You do NOT have to be running for them to work.... I will not have a rig without them......worth every penny.