My Kenmore dishwasher is a year and eight months old. After running it, I find a silver, glittery substance on the grooves of the top to my daughter's sippy cup. It's not much, about the size of a raisin, however I am concerned because my wife is pregnant and no one has any idea what this substance is. I suspect it may be due to the hard water, a part wearing down, or the soap (even though I've both granulated and liquid). Does anyone have any advice as to what it might be and what I should do?