Baking soda descaling When boiling water in an aluminum pot, put a spoonful of baking soda and boil it for a few minutes to remove the scale, or you can directly wipe it with household alkali.
Vinegar descaling If the kettle has scale, you can put a few spoonfuls of vinegar in the water and boil it to remove scale.
Remove the scale from the thermos, add some vinegar and broken egg skins or beans to the water and shake for a while.