Tetro says you can descale a coffee maker by running a brew cycle with one part water to one part vinegar. As long as you're deep-cleaning with vinegar or a store-bought descaling solution at least once a month, you'll be able to keep the germs, mineral deposits, and mold away.
Both distilled white vinegar and apple cider vinegar are acidic to the same 2.4-2.5 pH due to their 5% acetic acid content. The acid in both vinegars will clean and descale coffee maker heating elements and water lines exactly the same.