The SAFE dynamic model was applied to a ”clean rain” roof experiment performed within the EXMAN project. In the experiment ambient throughfall was removed and replaced with artificial ”clean throughfall”. Input of S, N and H to the forest ecosystem was reduced by 75–100%. The results of the modelling show, that the time scales of model predictions and experiments are the same. The change in base cation flux was well reproduced, while the simulation of changes in aluminum flux was less successful. pH stayed constant in the experiment as well as in the calculations.