PROBLEM TO BE SOLVED: To provide a fan for regulating a temperature of water in an aquarium, which is capable of improving the efficiency of the temperature control by increasing the amount of blowing air. SOLUTION: An outside air-sucking opening 10 is formed in a peripheral wall of a passage-forming pipe 2 for forming a blowing passage 3 of a fan 1. A narrowed passage 11 in which the cross-sectional area of the passage is reduced to the front side is formed at a position corresponding to the outside air-sucking opening 10, in the blowing passage 3 in the passage-forming pipe 2. COPYRIGHT: (C)2009,JPO&INPIT
