If distilled water is not available where you live, use bottled water. It will be important to clean the chamber each morning, do not leave standing water in the chamber between uses. The only care a CPAP, APAP or BiPAP machine requires is to clean or change the filters at the air intake.
What causes water in CPAP tubing?
The Role of the Humidifier in Causing Water Condensation. In most cases, moisture in the CPAP tubing or mask is secondary to the use of a heated humidifier. If the humidity setting is turned up, more moisture may be in the air to rain out within the tubes or mask.