What does it mean to open the door and release water in the lunar calendar?

It means that the water in the yard flows out in a good direction, and generally flows to the Tiangan level of the Twenty-four Mountains (Pan Tian). The air in the sky is clear, pure and not miscellaneous, which should be judged according to the actual situation.

If the external water flows from left to right, the main road of courtyard water collection flows from right to left.

If the external water flows from right to left, the courtyard water main road flows from left to right.

This is the best cooperation and the most correct way to interlock the true qi with sand and water.

(The information comes from Baidu Encyclopedia "Cut to the chase and let the water flow". )