The standard H5i water chamber is intended for use with the heated humidifier associated with the ResMed S9 CPAP and VPAP machines. Distilled water should be used in the ResMed S9 water chamber to prevent mineral build up. To avoid bacteria collection in the tub it is recommended that it be emptied on a daily basis. If you are traveling with your CPAP machine be sure to empty the water chamber before you pack it to avoid water damage.
This water chamber is not dishwasher safe, however, there is a cleanable water chamber option that can be taken apart and cleaned in your dishwasher.