Abstract: A siphon pipe applied to a container unit for hydroponics comprising a pipe which is an integrated molded U-shaped body, the pipe having a U-section and two straight sections, the U-section having a continuously varying cross-sectional profile with a long axial length which gradually increases from one end toward the top, and then gradually decreases from the top toward the other end, thereby forming a continuously varying cross-sectional profile of the U-section. When the water level in the container unit rises to the U-section of the siphon pipe, the water level in the siphon pipe rises rapidly and flows to the outlet of the siphon pipe, and at the same time the air inside the pipe is brought out, to achieve a high-efficiency siphoning effect.

Abstract: A container unit for hydroponics includes a container having an overflow unit and an outflow unit located therein. The overflow unit includes an overflow tube, and the outflow unit includes a siphon pipe which is height adjustable. A cover is mounted to the container and includes an opening, a first hole and a second hole. A pot is engaged with the opening of the cover. Two hooks are connected to the back of the container so as to be hooked to a shelve to form multiple rows of the containers between which the overflow tubes and the outflow tubes are connected via the first and second holes of the containers. The overflow tube and siphon pipe control the water level in the container to prevent plant root from being rotted.