Fish can bring in money. That is why you will often see fish ponds at the front of Chinese restaurants. There is a large aquarium at a Chinese laundry I go to when I am in New York. In addition, many times there will be eight red fish and one black fish. Nine is the ultimate yang number.
Odd numbers are yang, even numbers are yin.
Nine is a lucky number. Also, red is lucky. Speaking of color, according to the bagua, certain colors should be used in certain areas. Yes, every area on the bagua has a color related to it. Color is very important to all of us.