White buildup on dishwashed dishes can be a sign of a partially blocked soap distributor, hard water, or dissolved solids in your water supply. Follow the steps below to determine the source of white residue.
Test your water
Perform a hard water test on a hot water faucet. We recommend using a water testing kit or hardness test strips. These can both be found at most hardware stores. For direction, visit our Testing Water Hardness article.
Where does your water test on the hardness scale?
0-3 gpg or 0-50 ppm
Your water is soft. Confirm that the soap dispensers are not blocked in your dishwasher. If the white buildup continues over multiple cycles, the white residue is likely TDS (total dissolved solids) in your water. You'll want to get a sample of your water tested to see what, if any, additional filtration you may need.
Above 0-3 gpg or 0-50 ppm
Your water is testing hard. The white residue is likely hardness minerals settling on your dishes. To resolve this, follow our troubleshooting guide to confirm your softener is working.