Maintenance Contracts For The Hills District & Lower North Shore.. Swimming Pool Maintenance & Repairs - North Rocks, NSW . Service: Cleaning, Leak Detection. Kind: Above Ground, Fresh Water Systems. Equipment: Heaters, Lights, Pumps. Type: Commercial. Material: Concrete. Hours of Operation: Flexible Hours, Open Monday - Friday, Open Saturdays. Service Option: By Appointment. Payment Method: Cash, Cheques