From a health point of view, turn down the fire after boiling water, because nitrite will form if the water is burned for a long time. Nitrite is poisonous If you drink this water regularly, nitrite will accumulate in the body and cause poisoning. It can not only bind hemoglobin, but also cause cancer, so you can't drink boiled water many times! The same is true for cooking porridge. A small fire will be much better.