The tank is filled with room temperature water and both food-coloring dishes are fill with room temperature water. Place under the tank one-cup ice cold water and one with boiling hot water. Then fill your pipettes up with the food coloring. I use blue representing cold and red for hot. I continue to squeeze the pipettes multiple times so you can see the currents.
You can see the red is rising creating low pressure, as the hot air rises we can see the blue food coloring representing the cold air moving into replace the warm air that is rising. So it’s moving into the area with the low pressure.
This is a awesome representation of Convection. Which creates air movement.