The particles may be a sign that the fill tube in your hot water tank is deteriorating. If so, white particles (which may have a bluish tint) will show up in strainers in various locations in your house–washing machine, kitchen faucet, and shower head. These particles are plastic and will float on water and melt when heated at high temperatures. Most water heater companies will replace the fill tubes because they were flawed. Check the name of your tank, and call the company for instructions.