This is a traditional Chinese medicine health preserving method. Peacock fish refers to seven-color (or five-color) angelfish, which is one of the ornamental fish, meaning auspiciousness, beauty and happiness. In hot summer, people often put guppies in an aquarium in their bedroom or study to help them sleep and moisten their lungs. This is because in a well-lit environment, guppies can naturally regulate the body clock by secreting melatonin and other substances, so as to achieve the effect of sleeping and nourishing the mind. In addition, tiny water waves will float on the surface of the aquarium, which will also help relieve stress and promote relaxation.