I am experiencing white dust from my Guardian humidifier

If water is especially hard or has a high mineral content, you may notice white dust around the unit. If bothersome, you can use distilled water or you can buy one of our decalcification filters to help with that problem. You can visit our website www.lasko.com to see which filter would fit in your machine. Please note that the filter will help remove minerals from the water, but in cases where the water is extremely hard the filter may not remove all minerals. In that case you would need to use distilled water to avoid the white dust. The filter will last approximately 2 months depending on the quality of the water.