The variety of geomantic snakehead is a black geomantic fish, which has the function of blocking evil spirits and relieving evil spirits. Specifically, there are black-bodied fish such as Black Molly (Black Mary) and Butterfly-tailed Black Longan (Butterfly-tailed or Black Peony).
Among them, black Mary has a good effect of exorcism, and butterfly tail has both the function of attracting wealth and exorcism. If you want to keep fish away from evil spirits, it depends on whether your personal five elements are suitable or not.