How do I force trapped air inside at the top of a water container back down into the water using a small aquarium air pump and a 1/4" plastic tube? The pump will be outside the container. I want to use a Y connector or a one way Y valve (if available). I want the Y part to face up under the lid and one side of the Y is to be connected to a tube extruding through the lid to the pump on the outside. I need to be able to force the air in the air space under the lid down into the water to create air bubbles. The lid will not be air tight. How do I accomplish this without the outside forced air going back up the other side of the Y connector back into the air space instead of into the water by the connected tube at the bottom of the Y connector due to back pressure from the water?

Google aquarium air pump