Swimming pool cleaning machines; robotic swimming pool cleaning machines; swimming pool cleaning apparatus; sweeping machines for use in swimming pools; skimmers for cleaning swimming pool surfaces; swimming pool pumps; pumps for recycling water in swimming pools; pumping apparatus for dispensing chemicals into swimming pools; vacuum cleaner hoses for use in swimming pools; automatic cleaning and sweeping apparatus for swimming pools and components thereof; machines and apparatus for cleaning, sweeping and washing swimming pools and components thereof; high pressure cleaners and components thereof