The filtration system of the swimming pool is of high importance because it performs the functions of a mechanic cleaner of the water. If the system is able to catch even the smallest fragments you will have perfectly clean water in the pool. These fragments are then removed by cleaning the filter and by reverse washing out (in a sand filter system). Generally, before choosing a filtration system for your pool you need to know what its purpose will be. Here we will review two most common swimming pool filtration systems.