Sorry, no long-term effect

Have applied once to the previously cleaned with high-pressure cleaner concrete patio slabs impregnation as directed in the summer 2. At first I was very happy, easy color restoration and a beading effect were gearing for a few weeks. Unfortunately, the rain water also dried but from not as good and fast as before. But the main reason why I bought the impregnation, was the Vermoosen and the green color, particularly in the joints. Another reason was that plates should not become dirty so quickly and bird droppings, staining the leaves should be much easier to remove.
Unfortunately I had to find now after half a year that already green growth is noted on individual plates and in the joints.
Either I do it every six months new plan (which, however, in the winter is not possible), or I look around for a even better and especially longer-lasting product!