Grit on dishes usually means the filter is clogged and food particles are being sprayed back onto the load, or powder detergent isn't fully dissolving. Less often, the grit is sediment coming in with the water itself, especially after plumbing or water main work.
Quick diagnosis
| Symptom | Likely cause | First thing to try |
|---|---|---|
| Sandy specks on glasses in the top rack | Clogged filter recirculating particles | Remove and clean the filter |
| Grit mixed with food bits | Large food scraps overwhelming the filter | Scrape plates before loading |
| Powdery grains on dishes | Powder detergent not dissolving or clumped | Use fresh detergent stored dry |
| Dark, sand-like grains after plumbing work | Sediment from the water line | Run the kitchen tap until clear, then run an empty cycle |
| Grit mostly on the bottom rack | Clogged lower spray arm | Remove the arm and clear its holes |
A closer look
The filter
Most newer dishwashers use a filter you clean by hand, usually a cylinder and a flat mesh under the bottom rack. Older models often had a built-in grinder that chopped food so you never thought about it. When a manual filter goes uncleaned, particles pass back into the wash water and dry onto glasses as grit. Twist it out, rinse it under warm water and scrub the mesh with a soft brush.
Spray arms
Food and seeds that escape the filter end up in the spray arm holes. A partly blocked arm sprays unevenly and can push debris onto dishes instead of washing it away.
Detergent
Powder that has absorbed moisture clumps and doesn't dissolve fully. It can leave fine grains on dishes, especially in short or cool cycles. Keep detergent sealed, and try a liquid or pod if powder keeps leaving residue.
Sediment in the supply
When a water main is repaired or house plumbing is opened up, sand and rust particles can loosen in the pipes. Some get caught by the screen in the dishwasher's inlet valve; some get through. If grit showed up right after that kind of work, run the kitchen tap for a few minutes, then run the dishwasher empty.
Who runs into this most
People who moved from an older dishwasher with a grinder to a newer filter model, households that skip filter cleaning, and homes where street or plumbing work was done recently.
Prevention checklist
- •Clean the filter every week or two with heavy use
- •Scrape plates; you don't need to prerinse
- •Store detergent sealed and dry
- •Check spray arms whenever you clean the filter
Time to call a pro
- •Grit continues after the filter and spray arms are clean
- •Water is slow to fill or barely fills, which can mean a clogged inlet screen
- •Water stays in the bottom of the tub after the cycle ends
- •You find broken glass or plastic pieces in the sump
Travis's rule of thumb: Grit you can feel is almost always the filter. A film you can only see is usually the water.
A neglected filter draws more than grit: it's also what pulls ants into a dishwasher. For a cracked filter, a sump full of glass or a spray arm that won't seat, visit our dishwasher repair page or call (832) 552-1615.