[0009] U.S. Pat. Nos. 5,956,899 to

[0009] U.S. Pat. Nos. 5,956,899 to DiOrio (1999) revealed a self-watering device based on the same principle as 6,134,833 and 4,329,815. The DiOrio Patent does not have a planter. It provides a separate airtight reservoir, which is hanged on the sidewall of the container. A soil moisture sensor can be buried at different height levels of the soil. The reservoir has an outlet tube at the bottom of the reservoir. The outlet tube is connected to the bottom soil of the pot. When the moisture senor detects dryness of soil, it lets air pass through the venting tube to the reservoir. The atmospheric pressure forces water to flow from reservoir to the bottom soil of the planter. When the soil becomes wet, the sensing device shuts the airflow, which in turn shuts the water flow.