Our latest Ratings of nonphosphate gels, liquids, packs, pods, powders, and tablets show that a few left dishware sparkling. Many of the rest left food stuck to plates or pots, or caused aluminum to discolor. And if your home is among the more than 50 percent with hard water, take note: In just 20 washes using very hard water, several products allowed glassware to be covered with a frosty-white film (a residue of minerals) to varying degrees.
Readers started to notice a white buildup on glassware after phosphates were banned from dishwasher detergents two summers ago. (Phosphates helped to control water hardness, according to the American Cleaning Institute, a trade group.) So we added hard-water performance to our Ratings, which changed the rankings of some products. Finish Quantum tablets, top-rated in our last tests, slipped to third place.
There were even differences in removing our cooked-on goo (pudding, peanut butter, cream cheese, and 14 other ingredients painted on dishes in our tough tests). The best detergents left no leftovers; the worst, including eight products rated fair overall, left varying amounts of our mix.
No type of product was best overall, but liquids and gels tended to fall toward the bottom of the Ratings. Most dishwasher detergents now contain enzymes to aid in cleaning, and some have bleach, which may help remove stains like those made by tea. A Design for the Environment (DfE) label identifies products that have been assessed for potential human health and environmental effects.
Bottom line. Finish Powerball Tabs and Cascade Complete All In 1 ActionPacs clean dishes and pots very well and don't leave water spots, white film, or discolored aluminum. The Finish Powerball Tabs are also a CR Best Buy. A detergent sold in a hefty size will probably be cheaper, but those products—including Great Value (Walmart) and Kirkland Signature (Costco)—didn't clean very well.
Whatever detergent you use, you can get cleaner dishes by adding a rinse agent to your dishwasher, making sure the water is hot (120° F), and, when you load the machine, separating flatware and facing the dirty side of the dishes toward the water jets.