for three weeks the sand filter system is now in Betrieb.Und we always have clear water. For our pool just right. (Size 366/122 Diameter) The installation was very easy and thus the filter plant was built quickly It is also very easy to use. Rewind etc is very leicht.Bei our predecessors went it not so easy on the hand What I also impressed with this that no sand comes after rewinding into the pool. I can not report on the life indeed. I would recommend the filtration system .....