Every swimming pool need water to fill and to filter we need water filtration system. The dust enter in swimming pool are get cleaned by filter which settled on floor or in dissolved in water which can not be seen with naked eye. SO filter medium is needed for to clean the impurity form water and this is done by 3-4 kind of mediums 1. Sand 2. Cartridge, 3. De and 4. Filter bag. Second is the chemical composition of the water which make dust or impurity to settle down and also work for biological system of swimming pool. The alum and acid are used to keep the ph level of water in controlled manner with 7.6