An aquarium or water tank

摘要

Algae are prevented from growing on the inside of the side walls (1a, 1b, 1c, 1d) of an aquarium by attaching an ultrasonic vibrator (4) or vibrators (4) to the side wall or walls (1a, 1b, 1c, 1d) and the weak ultrasonic waves are generated from the ultrasonic vibrator or vibrators (4) and coupled to the side walls.