What is the materials needed in cleaning swimming pool?

It depends. If the plaster has an alkalinity build-up (a chalky white look on the plaster), you will need an acid wash. It is not something you would want to do yourself. Use a professional. If the tile has a white ring around it, that would be calcium. It will require specialized equipment to remove it. There are two methods: glass beads and magnesium sulfate. Magnesium sulfate is the newest method, and won't damage the tile. If the water is dirty, it could be a variety of reasons: pool equipment not operating properly, water chemistry unbalanced or improper circulation of water.