When the aluminum pot is boiling water, put a spoonful of baking soda and boil for a few minutes to remove the scale. CaCO3+2NaHCO3=Ca(HCO3)2+Na2CO3 (acetic acid and aluminum have to react, so acetic acid is not used).
If the kettle has scale, you can put a few spoonfuls of vinegar into the water. After boiling, the scale can be removed by .2hac+CaCO3 = H2O+CO2 =+Ca (AC) 2.
The main component of scale is CaCO3.