Patent ID: 8132533

Claim:
An aquarium overflow device for supplying water in an aquarium to an external device, the overflow device comprising: (a) an inverted U-shaped siphon pipe for supplying the water in the aquarium to an outside of the aquarium, the siphon pipe having an inlet side end portion to be disposed in the aquarium and an outlet side end portion to be disposed outside the aquarium, wherein the siphon pipe has an air inlet portion formed at an inlet side pipe portion of the siphon pipe so as to be located above the inlet side end portion, whereby, when a water level in the aquarium drops below the air inlet portion, air is introduced into the siphon pipe via the air inlet portion to thereby prevent water from being suctioned into the siphon pipe, and (b) an inverted U-shaped discharge pipe having an inlet side end portion to be disposed outside the aquarium and an outlet side end portion to be disposed inside the aquarium, wherein water forcibly supplied from an external device is introduced into the discharge pipe from the inlet side end portion and then discharged to the aquarium from the outlet side end portion, wherein the discharge pipe is provided with a backflow preventing hole at an upper portion thereof, and wherein, when forcible water supply from the external device is stopped, air is introduced into the discharge pipe from the backflow preventing hole to thereby prevent backflow of the water.