Air Bars are ideal for aquariums as it delivers oxygen for your fish vertebrae and plants. The small bubbles help saturate the water with oxygen with a lot of fish preferring higher levels of oxygen in water.
It also adds a fantastic look to your aquarium.
The bigger the air bar and the deeper the tank the stronger the air pump required. If you find air coming out of one end only this could be a case of the air pump not being strong enough. An easy way to test is to lift the air bar closer to the surface which should produce more air.