Raising feng shui koi fish, the quantity is extremely critical. The most popular way is to use nine. In the tradition of our country, nine is the highest number for Yang, which has a very noble meaning. There is a saying in Feng Shui that "three things are inexhaustible and six things are infinite". The six Dan Ding stands for "Good luck is better than good times", and the five red and white ones contain "five blessings". When it comes to "three sheep open Thailand", the saying of "Shuanglong playing in the water" is also widely circulated. 3, 6, 5, 9 and 2 are auspicious numbers to consolidate the prosperity of koi fish.