Important information about water:
Here are the published recommendations the US FDA and CDC regarding water used for saline nasal irrigation:
The US FDA advises using filtered, distilled, or previously boiled water for nasal irrigation: FDA Guidance.
The US CDC also provides detailed information about boiling, filtering, and disinfecting water for nasal irrigation: CDC Guidance.
New User Water Tip
Most users prefer to warm their water prior to use. If you do this, do not overheat the water. It should be lukewarm to the touch and not hotter than about 85°– 90°F (29°– 32°C).