Abstract: This invention discloses a covering comprising a floating member shaped as a square loop, one pair of opposite portions of which are inflatable members, and a water-proof sheet having a nipple downwardly formed thereon, which is loosely stretched inside the square ring of the floating member and the peripheral edge of which is tightly connected with the same. The covering can float on the water and shield the water from scorching sunshine, killing frost, strong wind and acid rain. It is adaptable, therefore, to be used in nursery pool to protect the crops raised therein from damage by extraordinary weather.

Abstract: An apparatus for clearing the deposition formed on the bottom of a pond comprises a filter device for filtering the deposition, a suction water tube provided in the filter device with a plurality of suction pipes radially connected to one end thereof and capable of swiveling along with the suction water tube, and a plurality of pipings to connect the water suction tube to the filter device. There are suction inlets formed on the suction pipes for aspirating the pond water which is then fed into the filter device through the pipings and filtered therein. There is also provided a driving mechanism for actuating the water suction tube together with those suction pipes connected thereto to slowly swivel in the water of the pond. The water in the culturing pond will be cleaned from time to time so as to provide a good water quality for the culturing of the fishes in the pond.

Abstract: The present invention relating to a device for regulating water flow in a water filter includes a valve base with six passages, a valve disc with two arcuate chambers rotatably disposed on the base in which the arcuate chambers may be arranged to communicate two pairs of the two adjacent of six passages of the base when the valve disc is turned to a predetermined position. The invention further includes a water inlet conduit adapted to be connected to a pump, an upper venting conduit for discharging water to a filter medium, a wash water outlet conduit, a clean water outlet conduit and a lower venting conduit which are communicated with the first, second, third, fifth and the sixth passages whereby the direction of water flow can be controlled by turning the valve disc to three predetermined positions.

Abstract: The present invention relates to an improved water filter which comprises a cone-shaped tank, a filtering bed layer, four conduits provided in the tank and concealed in the filtering bed and a four-way valve provided on the outer wall of the tank at the junction of the conduits which allows passage between any two adjacent conduits by means of a moveable plug operated in a predetermined turn so that the filtering and backwashing process of the tank can be easily controlled by the valve in practical use and the filtering bed is prevented from boiling and cracks along the side walls of the tank.