Standard Replacement of 12GPM HQUA Water Sterilizer. Maintenance Prerequisites: 1.Close the water supply of your system and drains all lines.Make sure the water in the chamber lower than the quartz sleeve. 2.Depressurize the unit.Place a small pail under the unit to catch any spills. Remove the UV lamp out. Notes: 1.Clean the quartz sleeve with a cloth soaked in CLR,vinegar or some other mild acid and then rinse with water. 2.Replace the tube if it cannot be cleaned completely or scratched or cracked.