All CPAP masks and headgear should be washed weekly. Just as you wash your pillowcases, washing your mask stops oils and germs from building up. We recommend Castile Soap - just a small amount will keep it all clean weekly.
Tubing and humidifier bowls should also be washed weekly, and if you are not using purified water, then add some vinegar and water (1:3) solution to remove calcification.
Do not hang any part of your CPAP in the sun, it will deteriorate quickly.