Over time, rust and mineral deposits can build up in your dishwasher. This can affect the performance, and detergents -- with or without phosphates -- end up being totally ineffective. Raid the pantry to clean out your dishwasher. Empty a packet of lemonade Kool-Aid into the compartment where you'd put detergent and run a full cycle on hot. The citric acid in the mixture helps clean away the gunk inside the machine.