If you see tiny white flecks on your just washed laundry, the most likely cause is washing powder that has not dissolved properly.
Check on your detergent packet that you are using the right quantity of powder for the type of water in your area.
Try running an extra rinse cycle on dark loads or reducing the size of the load.
If the problem happens when you run a quick-wash programme, it is likely that the powder has not had enough time to dissolve; it is better to use a liquid detergent for short wash cycles.
Various sources
