Why does the filter in the Mijia Smart Evaporative Humidifier Pro turn yellow after use?

This is due to the Mijia Smart Evaporative Humidifier Pro filter, which filters impurities from the air and water. This is normal and will not affect your use.
Here is more information on how to prevent the filter from turning yellow on the device:
1. Regularly check the filter for significant yellowing, buildup, or unusual odor.
2. Using clean or filtered water and cleaning the water tank regularly can help slow down filter yellowing.
3. If the filter becomes severely yellowed or shows signs of wear, it is recommended to replace the filter to maintain optimal humidification performance and air quality.