Are air pumps essential? We absolutely do recommend having an air pump for your aquarium... They essentially provide your tank with surface agitation, and without this, Oxygen that sits on the surface of the water can’t make its way into the water, and any excess carbon dioxide in the water can’t make its way out.
If you ever find your fish swimming at the surface of your aquarium, gasping at the surface, it means there isn’t enough oxygen in your tank. An air pump will fix this problem within minutes.