There are only four vital qi in the earthly branches: Zi, Wu, Mao and You, which are fire, water, wood and gold, so there is only the main qi in the sky.
For example, Chen, Xu and Chou do not follow their yin and yang, but fill in their main qi or their soil, and then fill in the remaining qi of the five elements. Old soil is spring, so the rest of the gas is ebony. Soil is the residual gas of gold, so fill in Jin Xin. Ugly soil is winter, so the residual gas is definitely clear water. The last time was in summer, so the residual air was Ding Huo.
Then, according to these theories, the twelve branches are filled with wood fire, water and soil, respectively, becoming the main gas and residual gas.
The main gas accounts for more than 70%- 100% of the strength.