opaline is correct about the fogger. I got it for around 50 buck, there are prob bigger units or cheaper ones...idk...but yeah again if you have a water source filled with minerals then it can collect on the device. Its a simple screw top with a little disk. The disk can be cleaned, but over a long period it will have to be replaced. I havent really looked into this yet, nor do i know how long it last. I figure if you maintain it well then it will last longer. Mineral salts can be cleaned with a solution of vinegar and water, maybe a rub from a toothbrush.