Since you pay attention to Feng Shui, the fish tank represents wealth. There are cornucopias, wealth and power (water). Generally, it should be placed in the God of Wealth at home to collect wealth, and should not be placed under the beam; nor It should be facing the entrance and exit doors. If there are evil spirits at the entrance and exit doors, a Feng Shui screen should be placed.
As for the position of the God of Wealth, it is usually on the diagonal to the left or right of the entrance. If you are particular about it, ask a Feng Shui master to decide according to the sitting direction of the house. According to the purple and white flying star in the eight houses, choose the prosperous side. That is.