In earlier times, the species of the Littorelletea were well represented in the 'Turnhouts Vennengebied' area. During the last decennia there was a sharp decline due to acidification and eutrophication. The possibilities for using the seedbank as a source for restoration is examined by means of a seedbank- analysis. Liming of the catchment area is conducted to improve the quality of the water in the 'zwart water' fen. The follow up of the change in water quality will be conducted by examining the water chamistry and the changes in the compsition of the phytoplancton and macrophyte communities. These characteristics will also be compared with fens which still contain a lot of the species of the Littorelletea, as as reference.