As oxygen transfer not only depends on bubble size (contact surface between gas and water) but to the same measure on the renewal of the gas bubble contact surfaces through turbulence of the waste water, ejectors – with their permanent circulation of the waste water – can so achieve a far higher oxygen efficiency compared to other aerators. With their inclined flow direction towards the floor Körting ejectors utilise the complete tank depth as entrance depth and avoid any deposits on the ground. A complete intermixing of the tank content is always guaranteed.