The majority of constructed systems are refinements of a German design by Professor Kilkuth. This was developed by him in the 1970’s, and the design has
played an important role in the subsequent development of treatment systems by reed plants. Many, many systems exist in 2016 as a result of this early
work by Professor Kilkuth. The use for Phragmites has accelerated faster with the introduction of stone bed systems. These systems take advantage of the plants ability to pass oxygen down
through the stems to the root zone, enabling the plant to survive and transfer oxygen downwards to the roots and the rhizomes, finally finding its way to the rhizosphere. The oxygen positively
enhances the activity by production of enzymes which attract the bacteria and work to break down the pollutants and pollution levels at the influent of the system.