Use distilled water to help keep the humidifier chamber clean and mineral deposit free. Tap water should not be used as it will leave hard white mineral deposits in the chamber as the water evaporates, or it may lead to mold growth. Cases of lung disease have been connected to using contaminated well water in a CPAP humidifier.</p><p> <b>What Is Distilled Water?</b> </p><p>Distilled water is created through the process of distillation. Basically, in the process of distillation, the pure H2O is boiled out of its contaminants. So, many of the contaminants found in water are inorganic minerals, metals etc. Those types of contaminants have very high melting points and even higher boiling points (way higher than the boiling point of water at 212 degrees F). So, as the water (with its contaminants) is boiled, the pure water turns into steam and is captured and cooled and thus becomes distilled water. The junk left behind is all of the contaminants.</p> <p><b>Benefits:</b><br> Prolongs the life of your CPAP or Bi-Level machine, Use distilled water to help keep the humidifier chamber clean and mineral deposit free.<br> 20-ounce bottles allow you to bring the water with you for travel.<br> Safely pack as many 20-ounce bottles as you need for your trip into your checked luggage. <br> No more searching for distilled water while on vacation. Just bring as many bottles as you need.<br> A 20-ounce bottle of CPAP H2O from No Insurance Medical Supplies will fill a standard humidifier chamber to the full line for most major brands such as Resmed, Respironics, and Fisher Paykel.</p>