Filters that are installed in such a way, via the diversity of the filtering plants, have an aesthetic role in gardens. In addition, they replicate wetlands, a necessary element in the development of natural life. Numerous helpers (insects, birds, amphibeans...) make their returns. It's a good path toward biodiversity. Phyto-purification is different from lagoon-based systems in that there is no water on the surface of the filters, but instead gravel--there is therefore no risk of the proliferation of mosquitos.