A ndreas Thon is professor of building technology in landscape architecture at Hochschule Geisenheim, where his research has, for over a decade, concerned itself with a single quietly subversive question: how water in a garden — a swimming pool, a pond, a small lake — can be kept clean by the plants in it, and what it would take for that to be the ordinary way of doing things, rather than the exception.
His doctorate, defended at Vechta in 2014, took apart the filter zone of a small bathing pond — how vegetation and flow conspire to do, slowly, what chlorine does briskly and badly. He has since published on evaporation, on filamentous algae, on the mineral substrate on which oligotrophic plants will actually thrive. He runs a water-plant nursery he founded as a spin-off from his Geisenheim research.
With Wolfram Kircher he wrote How to Build a Natural Swimming Pool — the practical English-language reference on a subject that, on the continent, has long since stopped being fringe.
