From the perspective of geomantic omen, there are two pairs of map fish at home, one red and one black. I wonder what it means from the perspective of geomantic omen.

Feng Shui is the law of nature. Not morality, not imagination. What fish you raise, what color fish you raise and how many fish you raise have nothing to do with Feng Shui! Proper placement of fish tanks will do some good to feng shui. However, closed and open, tall and short are very different, and many people's fish tanks have no good effect at all!