It creates a pressure on the air (high and low), thus the water pushes and pulls the air as the water level rises and falls with in the container.
If you want to add more air to you F&D totes, put an air stone in there that is on the same timer as your water pump(s)
But that would be the same air, not fresh air, no?
The air stone inside the tote is an interesting idea
Now that I put the rez air stone directly under the pump each time the pump is turned on it should bring fresh air into the tote as well