Besides water and nutrition, your plants also absorb oxygen through their roots. Therefore, an air pump is an essential part of an automatic irrigation system. With an ebb & flow or a drip irrigation system, you can place the included air stones directly in the nutrient tank. The pump can pump air to a depth of 1.3 meters. So make sure your water barrel is no higher than 1.3 meters. When using the pump in a hydro setup, air stones are best placed in the water of the grow tray itself. You then apply oxygen directly to the roots, which will lead to enormous growth for your plants.