Have you got cloudy marks like this on your glasses?
Take a cloth and wipe the item with some vinegar, if the white marks can be removed by the vinegar, then it is calcium deposits that have covered the item. The best way to overcome this problem is to add salt to the dishwasher water softener unit, or increase the dosage of salt to cope with hard water areas were the water supply may contain high amounts of calcium.
Turn the black pointer towards the '+' setting to make the water softener more effective. If you are using 'all in 1' tablets then it may be a good idea to use salt which will enhance your detergent tablet and improve the cleaning results from your dishwasher. If you are not sure if your water is hard, contact your local utility company for advice.