In Feng Shui class, how many fish is the best to keep at home?

The south left hexagrams and raised twenty-seven or nine red goldfish;

Four, nine or seven snakeheads, platinum fish or tropical fish are raised in the west;

Northwest Ganbu has a long life and raises snakehead, platinum fish and tropical fish for four, nine and six.

There are five, ten and eight species of yellow and white fish in Northeast China.