I often get calls similar to this client: Over the past several weeks-months, have been getting a whitish film/deposit on pots, tops of some plastic cups, etc. You don’t really see it on plates.
Typically this is caused when someone switches detergent usually to a liquid gel. It is almost always because we use too much soap.
One of my most appreciated recommendations follows:
My suggestion is to throw the liquid away and use the Cascade Complete or Finish tablets. Place one in the bottom of the dishwasher. Do not put them in the dispenser.
The reason for this is you want the soap (abrasive) at the front end of the cleaning process so that the last little bit of food that is left on the dishes (I’m assuming you are rinsing your dishes) is blasted off and then the dishwasher can “sanitize” the dishes with water that is too hot for you to handle. That is the real purpose of a dishwasher.
Keep in mind that if you rinse your dishes well before placing them in the dishwasher you can probably use the shortest cycle and save quite a bit of money on electricity and water over the course of a year.
Also, take a coffee cup and fill it half way with white vinegar and place it upright in the top rack with your next load of dishes. Do this for the next several loads and then once per month for as long as you own and use a dishwasher.